Gunmen opened fire at a Moscow concert hall on Friday killing at least 60 people, wounding more than 100 and sparking an inferno, authorities said, with the Islamic State group claiming responsibility.
Attackers dressed in camouflage uniforms entered the building, opened fire and threw a grenade or incendiary bomb, according to a journalist for the RIA Novosti news agency at the scene.
Fire quickly spread through the Crocus City concert hall in Moscow's northern Krasnogorsk suburb, as smoke filled the building and screaming visitors rushed to emergency exits.
Alexei, a music producer, was about to settle into his seat before the start of a rock concert when he heard gunfire and "a lot of screams".
"I realised right away that it was automatic gunfire and understood that most likely it's the worst: a terrorist attack," said Alexei, who would not give his last name.
As people ran towards emergency exits, "there was a terrible crush" with concert-goers climbing on one another's heads to get out, he added.
Russia's FSB security service said at least 60 people were killed and more than 100 others injured, according to Russian media reports.
Russia's Health Minister Mikhail Murashko said 115 people were hospitalised, including five children, one of whom was in grave condition. Of the 110 adult patients, 60 were in serious condition.
Authorities said a "terrorist" investigation had been started and President Vladimir Putin was receiving "constant" updates, his spokesman Dmitry Peskov told Russian news agencies.
Russia's national guard said it was on the scene and looking for the perpetrators. An AFP reporter saw police officers with sniffer dogs inspecting vehicles parked next to the building.
The Islamic State group said its fighters attacked "a large gathering" on Moscow's outskirts and "retreated to their bases safely".
Telegram news channels Baza and Mash, which are close to security forces, showed video images of flames and black smoke pouring from the hall.
Other images also showed concert-goers hiding behind seats or trying to escape.
Security services quoted by Interfax said between two and five people "wearing tactical uniforms and carrying automatic weapons" opened fire on guards at the entrance and then started shooting at the audience.
About 100 people escaped through the theatre basement, while others were sheltering on the roof, the emergency services ministry said on its Telegram channel.
Three helicopters were involved in efforts to put out the fire, dumping water on the giant concert hall that can hold several thousand people and has hosted top international artists.
Shortly after midnight, the emergencies ministry said the fire had been contained.
Also Watch: Putin, Zelenskyy invite PM Modi to Russia and Ukraine after elections: reports