National day of mourning in Russia after massacre

Moscow, Russia — Russia will observe a national day of mourning on Sunday after a massacre in a Moscow concert hall that killed more than 130 people, the deadliest attack in Europe to have been claimed by the Islamic State (IS) group.

Russian President Vladimir Putin has vowed to punish those behind the "barbaric terrorist attack", saying four gunmen trying to flee to Ukraine had been arrested.

Kyiv has strongly denied any connection, with Ukrainian President Volodymyr Zelensky accusing Putin of trying to shift the blame onto them.

"The whole country is in mourning with those who lost their loved ones in this inhumane tragedy," public television channel Russia 24 said on Sunday morning.

Putin, in his first public remarks on the attack, made no reference to a statement by IS claiming responsibility.

At least 133 people were killed when camouflaged gunmen stormed the Crocus City Hall, in Moscow's northern suburb of Krasnogorsk, and then set fire to the building on Friday evening.

The Islamic State group on Saturday wrote on Telegram that the attack was "carried out by four IS fighters armed with machine guns, a pistol, knives and firebombs," as part of "the raging war" with "countries fighting Islam".

A video lasting about a minute and half apparently shot by the gunmen has been posted on social media accounts typically used by IS, according to the SITE intelligence group.

The video appears to have been shot from the lobby of the concert venue and shows several individuals with blurred faces and garbled voices, firing assault rifles with inert bodies strewn about and a fire starting in the background.

The attack was the deadliest in Russia for almost two decades.

Russian officials expect the death toll to rise further, with more than 150 wounded.

Russia's Investigative Committee, which probes major crimes, said rescue workers were still pulling bodies from the burnt-out building on Saturday.

The emergency situations ministry has so far named 29 of the victims, the blaze having complicated the process of identification.

The ministry on Sunday posted a video of heavy equipment arriving at the scene of the fire to dismantle damaged structures and clear debris.

'Barbaric'

"Terrorists, murderers, non-humans... have only one unenviable fate: retribution and oblivion," Putin said in his televised address on Saturday.

Calling the attack a "barbaric, terrorist act", he said "all four direct perpetrators... all those who shot and killed people, have been found and detained."