RUSSIA held a day of mourning today for victims of a brutal terrorist attack on concert-goers in Moscow that killed at least 137 people.

Gunmen opened fire at the Crocus City Hall music venue in Krasnogorsk on Friday, killing scores and wounding over 150 others. Doctors continued to fight for the lives of over 100 wounded in hospital today and authorities said that the death toll could still rise.

The Islamic State (IS) group’s Afghanistan affiliate has claimed responsibility for the attack, a claim Russia has yet to comment on officially.

Addressing the Russian nation after the deadly shooting, President Putin said that 11 people in total had been arrested, including four gunmen, who fled the concert hall and made their way to the Bryansk region, about 210 miles south-west of Moscow, which borders Ukraine.

Mr Putin claimed that the suspects were caught as they attempted to flee to Ukraine through a “window” prepared for them on the Ukrainian side of the border.

He said all those arrested for the attack would be “justly and inevitably” punished as would anyone who ordered the “bloody, barbaric terrorist act.”

Kiev strongly denied any involvement and accused the Russian president of trying to blame it to shore up public support for his war against Ukraine, now in its third year.

President Volodymyr Zelensky said that it was a typical attempt by Mr Putin and “other thugs” to try to divert blame to Ukraine.

US intelligence officials said they confirmed Isis’s claim of responsibility.

National Security Council spokeswoman Adrienne Watson said: “Isis bears sole responsibility for this attack. There was no Ukrainian involvement whatsoever.”

Ms Watson claimed that the US shared information with Russia in early March about a planned terrorist attack in Moscow and issued a public warning to Americans in Russia, though Russian authorities deny having received such a warning.

Russian media broadcast videos that apparently showed the detention and interrogation of the suspects, including one who told the cameras he was paid to take part in the raid.

Russian news reports identified the gunmen as citizens of Tajikistan, a former Soviet republic in Central Asia that borders Afghanistan. 

Up to 1.5 million Tajiks have worked in Russia and many have Russian citizenship.

Dave Primov, who survived Friday’s attack, told reporters that the gunmen were “shooting directly into the crowd.

“People began to panic, started to run and collided with each other. Some fell down and others trampled on them.”

By the time they got out of the massive building 25 minutes later, it was engulfed in flames.