This page was edited by Jack Burgess, Johanna Chisholm, Emily McGarvey and Robert Plummer.
The writers were James Harness, Barbara Tasch, Ece Goksedef and Jake Lapham.
What we know about the attack on a Moscow concert hall
The attack on a Moscow concert hall on Friday was the worst in Russia for years. More than 100 people were killed as gunmen stormed the complex.
How did the attack unfold?
A rock band were due to perform to a packed Crocus City Hall on the outskirts of Moscow on Friday evening. Video showed at least four people wearing camouflage shooting randomly before proceeding into the concert hall itself and opening fire there.
Russian investigators said a flammable liquid was used to start a fire which engulfed the facade of the building.
Who are the Crocus City Hall victims?
As of Saturday afternoon, at least 133 people had been confirmed dead, while at least 60 remain in a serious condition.
Who are the attackers?
Russian MP Alexander Khinshtein said the attackers fled in a white Renault car, which was stopped by police in the Bryansk region about 340km (210 miles) away from Moscow.
Their identities have not been confirmed, but the Russian government says the four suspected gunmen who were arrested are not Russian citizens.
Who was behind the attack?
In a brief statement, the Islamic State (IS) said it was behind the attack. On Saturday, it released a photograph of what it said were the four attackers - all masked.
President Putin said the attackers were heading to Ukraine. However, Kyiv has denied any involvement.
In pictures: Security and flowers outside Moscow's concert venue
Pictures from the scene of Friday's attack reveal the damage to Crocus City Hall, in Krasnogorsk near Moscow.
Armed police patrol the area as people place flowers outside the venue, in memory of those who died.
Getty ImagesCopyright: Getty Images
An officer patrols the scene of the gun attack in Krasnogorsk, on the outskirts of MoscowImage caption: An officer patrols the scene of the gun attack in Krasnogorsk, on the outskirts of Moscow
ReutersCopyright: Reuters
A police officer stands next to a makeshift memorial to the victims of the shootingImage caption: A police officer stands next to a makeshift memorial to the victims of the shooting
ReutersCopyright: Reuters
Throughout the day people have placed flowers and lit candles at the memorial outside Crocus City HallImage caption: Throughout the day people have placed flowers and lit candles at the memorial outside Crocus City Hall
Getty ImagesCopyright: Getty Images
An advertising screen displays the slogan "Mourn" below an image of a lit candleImage caption: An advertising screen displays the slogan "Mourn" below an image of a lit candle
Analysis
Did Russia ignore US 'extremist' attacks warning?
Gordon Corera
Security correspondent
EPACopyright: EPA
There are always questions after any attack as to why it was not stopped or detected. But the Moscow attack raises particularly difficult issues for Vladimir Putin at a time of international tension and mistrust.
And much of that comes because of a warning from Washington.
The 7 March warning from the US to its own citizens was unusually specific. It talked of reports that "extremists" had "imminent plans to target large gatherings in Moscow" and specifically mentioned concerts. It advised Americans in the city to avoid large gatherings over the coming 48 hours.
The timing may not quite match, but other details do tally closely with events on 22 March.
There are channels through which intelligence is shared between countries - even those that are not allies - especially when it relates to possible attacks on civilians.
But the problem is that Moscow dismissed the warnings.
Read the full analysis by BBC Security correspondent Gordon Corera here
Fire at concert hall extinguished, Russian media reports
ReutersCopyright: Reuters
Russian media is reporting the fire at Moscow's Crocus Concert Hall has now been extinguished, citing Russia's ministry of emergency situations.
A large fire engulfed the interior and exterior of the complex, and investigators said it was started by the attackers using a flammable liquid. Glass on the top two floors of the seven-storey building also blew out.
Helicopters were brought in to drop about 160 tonnes of water to contain the blaze.
The roof of the auditorium has collapsed, and investigators will spend days sifting through the charred crime scene.
US 'strongly condemns deadly' Moscow attack, says Blinken
Will Vernon
Reporting from Washington DC
ReutersCopyright: Reuters
The US Secretary of State, Antony Blinken, has issued a
statement saying the United States “strongly condemns yesterday’s deadly
terrorist attack in Moscow,” and expressing “deepest condolences” to the loved
ones of all those affected.
Blinken added that Washington stands in solidarity “with the
people of Russia” and condemns “terrorism in all its forms".
Earlier, an unnamed official told the BBC’s partner CBS News
that US intelligence confirms the Islamic State group’s claim that it was
responsible for Friday’s attack.
A US National Security Council spokesperson confirmed last night
that America had shared information about an impending attack with the Russian
authorities earlier this month.
The White House National Security Communications Advisor John
Kirby, speaking yesterday at a briefing shortly after reports about the attack
in Moscow began to emerge, said, “There is no indication at this time that
Ukraine or Ukrainians were involved in the shooting".
The Russian Foreign Ministry reacted angrily to those remarks,
asking “On what basis can officials in Washington draw any kinds of conclusions
about somebody’s lack of involvement whilst a tragedy is unfolding? If the
United States has such information, they should share it. If they don’t have
any such information, then the White House has no right to absolve anyone.”
Four suspects are not Russian citizens, authorities say
The Russian government says that the four suspected gunmen arrested over yesterday's attacks are not Russian citizens.
"They are all foreign nationals," the interior ministry says in a statement.
As we reported earlier, the attackers identities have not been announced but unconfirmed reports have mentioned nationals from Tajikistan, and Russian MP Alexander Khinshtein said passports from the country had been found in the getaway car.
The Tajik Foreign Ministry earlier denied the involvement of its citizens in the attack.
Eyewitness: 'The gun shots were going on and on'
We're hearing more eyewitness accounts from people who were in Crocus City Hall last night during the attack.
You may find some of their descriptions distressing.
ReutersCopyright: Reuters
Margarita escaped last night's attackImage caption: Margarita escaped last night's attack
"We heard gun shots... the gun shots were going on and on. Then we went down to some kind of ground floor, some dark room and I saw only 'Exit' shining in the darkness... we just did not know whether to run or not," recalls Margarita.
"We came home yesterday... an ambulance came, and they gave us a sedative.
"You close your eyes and you see it, when you are left alone, you hear that. Today I express my condolences to everyone."
ReutersCopyright: Reuters
Anastasia Rodionova says people couldn't understand what was happeningImage caption: Anastasia Rodionova says people couldn't understand what was happening
Anastasia says the attackers were shooting without warning inside the music venue: "They were just walking and gunning down everyone methodically in silence. Sound was echoing and we could not understand what was where."
"I came home, my coat was just covered in blood. Apparently, someone shielded me."
Spectator neutralised concert hall attacker, says official
A concert-goer caught up in Moscow's Crocus City Hall attack yesterday "neutralised one of the terrorists", according to the Investigative Committee of Russia, a federal investigating authority.
The head of the committee says it plans to present the audience member, who they did not name, with a departmental award.
The committee says the man "showed unparalleled courage" as he tried to protect his wife when gunmen stormed the complex.
"With his active and decisive actions, he saved the lives of the people around him at that moment," it posted on Telegram.
I was shocked; I saw one exit and I followed the crowd - eyewitness
"Before the concert we heard noise in the hallway. Someone
was shooting and people were running out. I didn’t understand what happened. I
left my stuff except my coat and followed the crowd," Eva says.
She says she didn't see the faces of the attackers, just heard them as she rushed on to the street, and adds that she wants to thank the guards who "quickly opened the
exits".
"I was shocked, I saw one exit and I followed the crowd," Eva recalls, saying she was panicked but "many people were calm and disciplined" as she followed members of the orchestra out. They then crossed a bridge and hid in a church.
Eva adds that she hasn't heard from the dancers yet and that "too many people are suffering". She wants to go donate blood to help the victims of the attack now.
Even though she says she feels "lucky
because I was saved in the first wave of evacuation", Eva says she is still in shock.
BBC Verify
Adam Robinson, Olga Robinson and Shayan Sardarizadeh
Analysis
Russian TV airs fake video blaming Ukraine for Moscow attack
NTVCopyright: NTV
One of Russia's major channels, NTV, has broadcast a fake video
using AI-generated audio of a top Ukrainian security official in an attempt to
blame Ukraine for last night's attack.
In the video, which has also been widely shared
online, Ukraine's top security official Oleksiy Danilov appears to say: "It is
fun in Moscow today. I think it's a lot of fun. I would like to believe that we
will arrange such fun for them more often."
However, BBC Verify has established
that the video is a composite of two interviews published in the
last week. The voice of Danilov was likely generated using AI technology,
according to an expert.
The two interviews used to create the fake video can be accessed on
YouTube, one - dated 19 March - features
Danilov and the other - dated 16 March - Ukraine's
military intelligence chief Kyrylo Budanov.
The presenters interviewing Budanov can be seen in the fake NTV
video, wearing the exact same clothes with identical backgrounds behind
them.
The quote by Danilov which appears in the NTV video cannot be
heard in the original interview from 16 March, making it likely that the audio
is AI-generated.
Sam Gregory, an expert on AI-generated content, has told BBC Verify
that the video aired by NTV was likely a "deepfake" and Danilov's
voice in it appeared to be a "voice clone deepfake".
In pictures: Smoke rises from rubble in destroyed concert hall
More images from the Russian Investigative Committee press-service reveal the catastrophic damage inside the music venue.
Earlier Moscow's regional governor, Andrei Vorobyov, who visited the site of Friday's attack, said 20 more bodies were found beneath the rubble by rescue workers.
Andrei says the remains of the ceiling are in danger of collapse.
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock
Smoke rises from the remains of the hall, gutted by fire last nightImage caption: Smoke rises from the remains of the hall, gutted by fire last night
EPACopyright: EPA
Russian investigators working inside the burned Crocus City Hall concert venueImage caption: Russian investigators working inside the burned Crocus City Hall concert venue
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock
The auditorium's roof collapsed from fire damage after the attackImage caption: The auditorium's roof collapsed from fire damage after the attack
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock
Other parts of the building were also damaged in the fireImage caption: Other parts of the building were also damaged in the fire
EU and Nato condemn the attack in Russia
Getty ImagesCopyright: Getty Images
We've been hearing more reactions from around the world after last night's attack on the outskirts of Moscow.
EU policy chief Josep Borrell has shared a post on X, formerly known as Twitter, which condemns "in the strongest terms the heinous attack perpetrated outside Moscow last night". He goes on to say "terrorism has targeted again defenceless people.
The international community must remain firmly united against the scourge of terrorism"
Ursula von der Leyen, the President of the EU Commission, has also "strongly condemned" the attack against civilians "claimed by the Islamic State" in a post on X. "My thoughts are with the victims and their families during this tragic time," she adds
Nato spokesperson Farah Dakhlallah has also condemned the attack on X. She says "we unequivocally condemn the attacks targeting concertgoers in Moscow. Nothing can justify such heinous crimes. Our deepest condolences to the victims and their families"
Poland's PM, Donald Tusk, has said on X that his country "strongly condemns the brutal attack" and hopes "this terrible tragedy will not become a pretext for anyone to escalate violence and aggression"
Elsewhere, Turkey's Recep Tayyip Erdogan has condemned the attack "in strongest terms" and sends condolences to the "Russian people and the government"
We could still hear bursts of shooting behind us - eyewitness
Paul Kirby
Europe digital editor
Margarita Bunova had just got hold of opera glasses for the show when she heard what she thought were firecrackers, which then turned into rapid bursts that she and her husband identified as gunfire.
"Somebody said run downstairs and it was complete darkness... we could still hear bursts of shooting behind us by the time we got out."
One man in a VIP box told how he and others barricaded themselves in only to find smoke billowing through the theatre.
Another man, Vitaly, saw the attack unfolding from a balcony: "They threw some petrol bombs, everything started burning."
Whether it was a petrol bomb or another incendiary device, the flames spread rapidly.
Video content
Video caption: Footage shows people taking cover inside the venue as multiple shots are heardFootage shows people taking cover inside the venue as multiple shots are heard
Firefighters could not get near the building because of the attack. The fire soon spread to the roof and could be seen across the skyline in Krasnogorsk.
Part of the roof collapsed and the fire spread to the front of the building, gutting the top two floors.
Many of those in the auditorium fled through the foyer.
Recap: The latest on the Moscow concert hall attack
ReutersCopyright: Reuters
It's been a fast moving day of developments as authorities work to establish details around one of Russia's worst attacks. Here are the latest developments:
Rescuers are still searching through the charred remains of Moscow's Crocus City Hall after last night's attack, where at least 133 people were killed in a concert hall shooting
The death toll is expected to "rise significantly", according to the city's governor
President Vladimir Putin has made his first public statement since the attack, vowing to punish those responsible
Putin has declared a day of mourning for Sunday 24 March
He said all four gunmen have been arrested, and claimed they were trying to escape towards Ukraine and had people willing to help them do so
Accusations of Ukrainian involvement have been labelled as "absurd" by Kyiv
According to an unverified statement online, militant group Islamic State said it was behind the attack
Muscovites are continuing to queue to donate blood for those injured and flower tributes have been placed at the scene of the attack
IS group is a threat to us all, UN Secretary-General says
ReutersCopyright: Reuters
We can bring you some reaction to the attack in Moscow from United Nations Secretary-General Antonio Guterres now.
He's on a visit to Egypt where he's been speaking at the Rafah border crossing.
The Islamic State group is a "very serious threat to us all", Guterres has said.
"We firmly condemn, we consider absolutely intolerable the attack that took place in Moscow.
"And we encourage all countries to co-operate with each other in order to make sure that ISIS will not have the capacity to strike again anywhere else in the world," he says.
As a reminder, the IS group has claimed responsibility for the concert attack.
Russia has not yet commented on the claims but the US has said it's credible that the group's behind the attack.
Suspects used getaway car, Russian authorities say
ReutersCopyright: Reuters
Russian authorities said the attackers used this car to escape the Krasnogorsk attackImage caption: Russian authorities said the attackers used this car to escape the Krasnogorsk attack
Russian MP Alexander Khinshtein said the attackers fled in a white Renault car. According to him, police tried to stop the vehicle in the Bryansk region, about 340km (210 miles) away from Moscow, managing to arrest two people as the others fled.
Some 14 hours after the first reports of shooting, Russia's FSB security service announced 11 people had been arrested, including four "directly involved".
Their identities have not been announced. Unconfirmed reports have mentioned nationals from Tajikistan - Khinshtein said passports from the country had been found in the car.
The photo above was distributed by Russian authorities and the BBC is unable to verify its authenticity, or if the car is indeed linked to the Moscow attack.
People initially thought they heard firecrackers, says attack eyewitness
We've been hearing from some of the people caught up in last night's deadly attack on Moscow's Crocus Concert Hall.
One woman was with her 11-year-old daughter, buying ice cream at a café near the entrance, when they heard the noise and someone shouted to get down on the floor.
"We rushed to the children, lay down and started setting up barricades from tables and chairs, and several wounded people came running to us," a woman who was at the café with her 11-year-old daughter, has told BBC Russian.
Inside the theatre, the concert had been due to start in just a few minutes and some thought the noise might be part of the act.
AFPCopyright: AFP
Survivors told of panic inside the building as people tried to escapeImage caption: Survivors told of panic inside the building as people tried to escape
Sofiko Kvirikashvili heard what she initially thought was "some kind of endless burst of firecrackers - I turned around in the hall once, then again. The third time, I realised everyone in the hall had started running away in all directions."
Dave Primov, the photographer, said there was a crush and a scene of panic. Some in the theatre tried to lie down between the seats, but with several gunmen opening fire in the stalls, that offered little protection.
Those in the audience who could, headed for the stage. Others tried to find higher exits, only to find some of the doors locked. Eyewitnesses said there were elderly people as well as children there, all caught up in the attack.
The Islamic State group has issued a follow-up statement
offering more details about last night’s attack on a concert hall on the outskirts
of Moscow, which the group earlier said it was behind.
The new details - published via IS group accounts on messaging app Telegram - say four
attackers were involved in the deadly assault, and includes a picture claiming
to show the four assailants, all masked. The update comes from the group's news
outlet Amaq, which was also the source of the initial claim.
Neither of the two IS Amaq statements indicated which of IS's
regional branches was responsible for the attack.
In terms of motive, Amaq says "the attack comes in the context of normal ongoing war between the Islamic State and [anti-Islam] countries".
The IS mouthpiece says the attack was carried out by "fighters" who it says were armed with "machine guns, a gun, knives and incendiary bombs", and that the attack was preceded by a "concerted" reconnaissance mission.
Russia has not yet commented on the claims but the US has said it's credible that the Islamic State group could be behind the attack.
Analysis
Ukraine concerned Russia will use attack to escalate war
Sarah Rainsford
BBC Eastern Europe Correspondent in Kyiv
Officials here in Kyiv moved quickly to rule out any link to the Moscow gun attack. The foreign ministry, a presidential adviser and the military intelligence agency all say, categorically, that Ukraine was not involved – and that its war with Russia will be decided on the battlefield.
The Russian FSB security service is claiming the Moscow attackers were caught on their way to Ukraine, and that they had contacts on the other side supporting them. But an intelligence representative here, has called the idea the gunmen would head for the Ukrainian border "absurd".
Andriy Yusov, a representative of Ukrainian defence intelligence, told the BBC the area is full of Russian military and security services. Any gunman fleeing the scene of an attack would have to be "stupid or suicidal" – or want to get caught - to head there, says Yusov.
The fear in Kyiv is that Russia will use the attack to escalate its aggression against Ukraine even further, that blaming Kyiv, with its Western allies, will be a way of rallying support for President Vladimir Putin and his full-scale invasion - and mobilising more Russian soldiers, for that fight.
Live Reporting
Edited by Robert Plummer
All times stated are UK
Get involved
- Bullets and panic - the Moscow concert that became a massacre
- The latest on what we know about the attack
- The attack raises particularly difficult issues for Vladimir Putin at a time of international tension and mistrust
Getty ImagesCopyright: Getty Images An officer patrols the scene of the gun attack in Krasnogorsk, on the outskirts of MoscowImage caption: An officer patrols the scene of the gun attack in Krasnogorsk, on the outskirts of Moscow 
ReutersCopyright: Reuters A police officer stands next to a makeshift memorial to the victims of the shootingImage caption: A police officer stands next to a makeshift memorial to the victims of the shooting 
ReutersCopyright: Reuters Throughout the day people have placed flowers and lit candles at the memorial outside Crocus City HallImage caption: Throughout the day people have placed flowers and lit candles at the memorial outside Crocus City Hall 
Getty ImagesCopyright: Getty Images An advertising screen displays the slogan "Mourn" below an image of a lit candleImage caption: An advertising screen displays the slogan "Mourn" below an image of a lit candle Analysis
EPACopyright: EPA -
Read the full analysis by BBC Security correspondent Gordon Corera here
ReutersCopyright: Reuters 
ReutersCopyright: Reuters 
ReutersCopyright: Reuters Margarita escaped last night's attackImage caption: Margarita escaped last night's attack 
ReutersCopyright: Reuters Anastasia Rodionova says people couldn't understand what was happeningImage caption: Anastasia Rodionova says people couldn't understand what was happening 
REUTERS/Yulia MorozovaCopyright: REUTERS/Yulia Morozova 
NTVCopyright: NTV 
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock Smoke rises from the remains of the hall, gutted by fire last nightImage caption: Smoke rises from the remains of the hall, gutted by fire last night 
EPACopyright: EPA Russian investigators working inside the burned Crocus City Hall concert venueImage caption: Russian investigators working inside the burned Crocus City Hall concert venue 
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock The auditorium's roof collapsed from fire damage after the attackImage caption: The auditorium's roof collapsed from fire damage after the attack 
Handout via EPA-EFE/REX/ShutterstockCopyright: Handout via EPA-EFE/REX/Shutterstock Other parts of the building were also damaged in the fireImage caption: Other parts of the building were also damaged in the fire 
Getty ImagesCopyright: Getty Images -
EU policy chief Josep Borrell has shared a post on X, formerly known as Twitter, which condemns "in the strongest terms the heinous attack perpetrated outside Moscow last night". He goes on to say "terrorism has targeted again defenceless people.
The international community must remain firmly united against the scourge of terrorism"
- Ursula von der Leyen, the President of the EU Commission, has also "strongly condemned" the attack against civilians "claimed by the Islamic State" in a post on X. "My thoughts are with the victims and their families during this tragic time," she adds
- Nato spokesperson Farah Dakhlallah has also condemned the attack on X. She says "we unequivocally condemn the attacks targeting concertgoers in Moscow. Nothing can justify such heinous crimes. Our deepest condolences to the victims and their families"
- Poland's PM, Donald Tusk, has said on X that his country "strongly condemns the brutal attack" and hopes "this terrible tragedy will not become a pretext for anyone to escalate violence and aggression"
-
Elsewhere, Turkey's Recep Tayyip Erdogan has condemned the attack "in strongest terms" and sends condolences to the "Russian people and the government"
Video caption: Footage shows people taking cover inside the venue as multiple shots are heardFootage shows people taking cover inside the venue as multiple shots are heard 
ReutersCopyright: Reuters - Rescuers are still searching through the charred remains of Moscow's Crocus City Hall after last night's attack, where at least 133 people were killed in a concert hall shooting
- The death toll is expected to "rise significantly", according to the city's governor
- President Vladimir Putin has made his first public statement since the attack, vowing to punish those responsible
-
Putin has declared a day of mourning for Sunday 24 March
- He said all four gunmen have been arrested, and claimed they were trying to escape towards Ukraine and had people willing to help them do so
- Accusations of Ukrainian involvement have been labelled as "absurd" by Kyiv
-
According to an unverified statement online, militant group Islamic State said it was behind the attack
- Muscovites are continuing to queue to donate blood for those injured and flower tributes have been placed at the scene of the attack
ReutersCopyright: Reuters 
ReutersCopyright: Reuters Russian authorities said the attackers used this car to escape the Krasnogorsk attackImage caption: Russian authorities said the attackers used this car to escape the Krasnogorsk attack 
AFPCopyright: AFP Survivors told of panic inside the building as people tried to escapeImage caption: Survivors told of panic inside the building as people tried to escape 
VASILY PRUDNIKOV/EPA-EFE/REX/ShutterstockCopyright: VASILY PRUDNIKOV/EPA-EFE/REX/Shutterstock Analysis
Latest PostOur live coverage is closing
We're now closing our live coverage of the attack at Moscow's Crocus Concert Hall, where more than 100 people have died.
The BBC has extensive coverage and analysis of events from Moscow at the links below:
This page was edited by Jack Burgess, Johanna Chisholm, Emily McGarvey and Robert Plummer.
The writers were James Harness, Barbara Tasch, Ece Goksedef and Jake Lapham.
What we know about the attack on a Moscow concert hall
The attack on a Moscow concert hall on Friday was the worst in Russia for years. More than 100 people were killed as gunmen stormed the complex.
How did the attack unfold?
A rock band were due to perform to a packed Crocus City Hall on the outskirts of Moscow on Friday evening. Video showed at least four people wearing camouflage shooting randomly before proceeding into the concert hall itself and opening fire there.
Russian investigators said a flammable liquid was used to start a fire which engulfed the facade of the building.
Who are the Crocus City Hall victims?
As of Saturday afternoon, at least 133 people had been confirmed dead, while at least 60 remain in a serious condition.
Who are the attackers?
Russian MP Alexander Khinshtein said the attackers fled in a white Renault car, which was stopped by police in the Bryansk region about 340km (210 miles) away from Moscow.
Their identities have not been confirmed, but the Russian government says the four suspected gunmen who were arrested are not Russian citizens.
Who was behind the attack?
In a brief statement, the Islamic State (IS) said it was behind the attack. On Saturday, it released a photograph of what it said were the four attackers - all masked.
President Putin said the attackers were heading to Ukraine. However, Kyiv has denied any involvement.
Read the full story here.
In pictures: Security and flowers outside Moscow's concert venue
Pictures from the scene of Friday's attack reveal the damage to Crocus City Hall, in Krasnogorsk near Moscow.
Armed police patrol the area as people place flowers outside the venue, in memory of those who died.
Did Russia ignore US 'extremist' attacks warning?
Gordon Corera
Security correspondent
There are always questions after any attack as to why it was not stopped or detected. But the Moscow attack raises particularly difficult issues for Vladimir Putin at a time of international tension and mistrust.
And much of that comes because of a warning from Washington.
The 7 March warning from the US to its own citizens was unusually specific. It talked of reports that "extremists" had "imminent plans to target large gatherings in Moscow" and specifically mentioned concerts. It advised Americans in the city to avoid large gatherings over the coming 48 hours.
The timing may not quite match, but other details do tally closely with events on 22 March.
There are channels through which intelligence is shared between countries - even those that are not allies - especially when it relates to possible attacks on civilians.
But the problem is that Moscow dismissed the warnings.
Fire at concert hall extinguished, Russian media reports
Russian media is reporting the fire at Moscow's Crocus Concert Hall has now been extinguished, citing Russia's ministry of emergency situations.
A large fire engulfed the interior and exterior of the complex, and investigators said it was started by the attackers using a flammable liquid. Glass on the top two floors of the seven-storey building also blew out.
Helicopters were brought in to drop about 160 tonnes of water to contain the blaze.
The roof of the auditorium has collapsed, and investigators will spend days sifting through the charred crime scene.
US 'strongly condemns deadly' Moscow attack, says Blinken
Will Vernon
Reporting from Washington DC
The US Secretary of State, Antony Blinken, has issued a statement saying the United States “strongly condemns yesterday’s deadly terrorist attack in Moscow,” and expressing “deepest condolences” to the loved ones of all those affected.
Blinken added that Washington stands in solidarity “with the people of Russia” and condemns “terrorism in all its forms".
Earlier, an unnamed official told the BBC’s partner CBS News that US intelligence confirms the Islamic State group’s claim that it was responsible for Friday’s attack.
A US National Security Council spokesperson confirmed last night that America had shared information about an impending attack with the Russian authorities earlier this month.
The White House National Security Communications Advisor John Kirby, speaking yesterday at a briefing shortly after reports about the attack in Moscow began to emerge, said, “There is no indication at this time that Ukraine or Ukrainians were involved in the shooting".
The Russian Foreign Ministry reacted angrily to those remarks, asking “On what basis can officials in Washington draw any kinds of conclusions about somebody’s lack of involvement whilst a tragedy is unfolding? If the United States has such information, they should share it. If they don’t have any such information, then the White House has no right to absolve anyone.”
Four suspects are not Russian citizens, authorities say
The Russian government says that the four suspected gunmen arrested over yesterday's attacks are not Russian citizens.
"They are all foreign nationals," the interior ministry says in a statement.
As we reported earlier, the attackers identities have not been announced but unconfirmed reports have mentioned nationals from Tajikistan, and Russian MP Alexander Khinshtein said passports from the country had been found in the getaway car.
The Tajik Foreign Ministry earlier denied the involvement of its citizens in the attack.
Eyewitness: 'The gun shots were going on and on'
We're hearing more eyewitness accounts from people who were in Crocus City Hall last night during the attack.
You may find some of their descriptions distressing.
"We heard gun shots... the gun shots were going on and on. Then we went down to some kind of ground floor, some dark room and I saw only 'Exit' shining in the darkness... we just did not know whether to run or not," recalls Margarita.
"We came home yesterday... an ambulance came, and they gave us a sedative.
"You close your eyes and you see it, when you are left alone, you hear that. Today I express my condolences to everyone."
Anastasia says the attackers were shooting without warning inside the music venue: "They were just walking and gunning down everyone methodically in silence. Sound was echoing and we could not understand what was where."
"I came home, my coat was just covered in blood. Apparently, someone shielded me."
Spectator neutralised concert hall attacker, says official
A concert-goer caught up in Moscow's Crocus City Hall attack yesterday "neutralised one of the terrorists", according to the Investigative Committee of Russia, a federal investigating authority.
The head of the committee says it plans to present the audience member, who they did not name, with a departmental award.
The committee says the man "showed unparalleled courage" as he tried to protect his wife when gunmen stormed the complex.
"With his active and decisive actions, he saved the lives of the people around him at that moment," it posted on Telegram.
I was shocked; I saw one exit and I followed the crowd - eyewitness
Eva, a wardrobe assistant to the band Picnic’s backing dancers, was backstage when the attack happened.
Speaking to Newshour on the BBC World Service, she says she was there with two dancers when they heard noises from outside.
"Before the concert we heard noise in the hallway. Someone was shooting and people were running out. I didn’t understand what happened. I left my stuff except my coat and followed the crowd," Eva says.
She says she didn't see the faces of the attackers, just heard them as she rushed on to the street, and adds that she wants to thank the guards who "quickly opened the exits".
"I was shocked, I saw one exit and I followed the crowd," Eva recalls, saying she was panicked but "many people were calm and disciplined" as she followed members of the orchestra out. They then crossed a bridge and hid in a church.
Eva adds that she hasn't heard from the dancers yet and that "too many people are suffering". She wants to go donate blood to help the victims of the attack now.
Even though she says she feels "lucky because I was saved in the first wave of evacuation", Eva says she is still in shock.
BBC Verify
Adam Robinson, Olga Robinson and Shayan Sardarizadeh
Russian TV airs fake video blaming Ukraine for Moscow attack
One of Russia's major channels, NTV, has broadcast a fake video using AI-generated audio of a top Ukrainian security official in an attempt to blame Ukraine for last night's attack.
In the video, which has also been widely shared online, Ukraine's top security official Oleksiy Danilov appears to say: "It is fun in Moscow today. I think it's a lot of fun. I would like to believe that we will arrange such fun for them more often."
However, BBC Verify has established that the video is a composite of two interviews published in the last week. The voice of Danilov was likely generated using AI technology, according to an expert.
The two interviews used to create the fake video can be accessed on YouTube, one - dated 19 March - features Danilov and the other - dated 16 March - Ukraine's military intelligence chief Kyrylo Budanov.
The presenters interviewing Budanov can be seen in the fake NTV video, wearing the exact same clothes with identical backgrounds behind them.
The quote by Danilov which appears in the NTV video cannot be heard in the original interview from 16 March, making it likely that the audio is AI-generated.
Sam Gregory, an expert on AI-generated content, has told BBC Verify that the video aired by NTV was likely a "deepfake" and Danilov's voice in it appeared to be a "voice clone deepfake".
In pictures: Smoke rises from rubble in destroyed concert hall
More images from the Russian Investigative Committee press-service reveal the catastrophic damage inside the music venue.
Earlier Moscow's regional governor, Andrei Vorobyov, who visited the site of Friday's attack, said 20 more bodies were found beneath the rubble by rescue workers.
Andrei says the remains of the ceiling are in danger of collapse.
EU and Nato condemn the attack in Russia
We've been hearing more reactions from around the world after last night's attack on the outskirts of Moscow.
We could still hear bursts of shooting behind us - eyewitness
Paul Kirby
Europe digital editor
Margarita Bunova had just got hold of opera glasses for the show when she heard what she thought were firecrackers, which then turned into rapid bursts that she and her husband identified as gunfire.
"Somebody said run downstairs and it was complete darkness... we could still hear bursts of shooting behind us by the time we got out."
One man in a VIP box told how he and others barricaded themselves in only to find smoke billowing through the theatre.
Another man, Vitaly, saw the attack unfolding from a balcony: "They threw some petrol bombs, everything started burning."
Whether it was a petrol bomb or another incendiary device, the flames spread rapidly.
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Firefighters could not get near the building because of the attack. The fire soon spread to the roof and could be seen across the skyline in Krasnogorsk.
Part of the roof collapsed and the fire spread to the front of the building, gutting the top two floors.
Many of those in the auditorium fled through the foyer.
Read more on this story here.
Recap: The latest on the Moscow concert hall attack
It's been a fast moving day of developments as authorities work to establish details around one of Russia's worst attacks. Here are the latest developments:
IS group is a threat to us all, UN Secretary-General says
We can bring you some reaction to the attack in Moscow from United Nations Secretary-General Antonio Guterres now.
He's on a visit to Egypt where he's been speaking at the Rafah border crossing.
The Islamic State group is a "very serious threat to us all", Guterres has said.
"We firmly condemn, we consider absolutely intolerable the attack that took place in Moscow.
"And we encourage all countries to co-operate with each other in order to make sure that ISIS will not have the capacity to strike again anywhere else in the world," he says.
As a reminder, the IS group has claimed responsibility for the concert attack.
Russia has not yet commented on the claims but the US has said it's credible that the group's behind the attack.
Suspects used getaway car, Russian authorities say
Russian MP Alexander Khinshtein said the attackers fled in a white Renault car. According to him, police tried to stop the vehicle in the Bryansk region, about 340km (210 miles) away from Moscow, managing to arrest two people as the others fled.
Some 14 hours after the first reports of shooting, Russia's FSB security service announced 11 people had been arrested, including four "directly involved".
Their identities have not been announced. Unconfirmed reports have mentioned nationals from Tajikistan - Khinshtein said passports from the country had been found in the car.
The photo above was distributed by Russian authorities and the BBC is unable to verify its authenticity, or if the car is indeed linked to the Moscow attack.
People initially thought they heard firecrackers, says attack eyewitness
We've been hearing from some of the people caught up in last night's deadly attack on Moscow's Crocus Concert Hall.
One woman was with her 11-year-old daughter, buying ice cream at a café near the entrance, when they heard the noise and someone shouted to get down on the floor.
"We rushed to the children, lay down and started setting up barricades from tables and chairs, and several wounded people came running to us," a woman who was at the café with her 11-year-old daughter, has told BBC Russian.
Inside the theatre, the concert had been due to start in just a few minutes and some thought the noise might be part of the act.
Sofiko Kvirikashvili heard what she initially thought was "some kind of endless burst of firecrackers - I turned around in the hall once, then again. The third time, I realised everyone in the hall had started running away in all directions."
Dave Primov, the photographer, said there was a crush and a scene of panic. Some in the theatre tried to lie down between the seats, but with several gunmen opening fire in the stalls, that offered little protection.
Those in the audience who could, headed for the stage. Others tried to find higher exits, only to find some of the doors locked. Eyewitnesses said there were elderly people as well as children there, all caught up in the attack.
Read more on this story here.
IS group shares more details on Moscow attack
BBC Monitoring
The Islamic State group has issued a follow-up statement offering more details about last night’s attack on a concert hall on the outskirts of Moscow, which the group earlier said it was behind.
The new details - published via IS group accounts on messaging app Telegram - say four attackers were involved in the deadly assault, and includes a picture claiming to show the four assailants, all masked. The update comes from the group's news outlet Amaq, which was also the source of the initial claim.
Neither of the two IS Amaq statements indicated which of IS's regional branches was responsible for the attack.
In terms of motive, Amaq says "the attack comes in the context of normal ongoing war between the Islamic State and [anti-Islam] countries".
The IS mouthpiece says the attack was carried out by "fighters" who it says were armed with "machine guns, a gun, knives and incendiary bombs", and that the attack was preceded by a "concerted" reconnaissance mission.
Russia has not yet commented on the claims but the US has said it's credible that the Islamic State group could be behind the attack.
Ukraine concerned Russia will use attack to escalate war
Sarah Rainsford
BBC Eastern Europe Correspondent in Kyiv
Officials here in Kyiv moved quickly to rule out any link to the Moscow gun attack. The foreign ministry, a presidential adviser and the military intelligence agency all say, categorically, that Ukraine was not involved – and that its war with Russia will be decided on the battlefield.
The Russian FSB security service is claiming the Moscow attackers were caught on their way to Ukraine, and that they had contacts on the other side supporting them. But an intelligence representative here, has called the idea the gunmen would head for the Ukrainian border "absurd".
Andriy Yusov, a representative of Ukrainian defence intelligence, told the BBC the area is full of Russian military and security services. Any gunman fleeing the scene of an attack would have to be "stupid or suicidal" – or want to get caught - to head there, says Yusov.
The fear in Kyiv is that Russia will use the attack to escalate its aggression against Ukraine even further, that blaming Kyiv, with its Western allies, will be a way of rallying support for President Vladimir Putin and his full-scale invasion - and mobilising more Russian soldiers, for that fight.