40 people have died and more than 100 have been wounded in an attack at a Moscow concert hall, Russia’s Federal Security Service says. 

The attack, which Russian authorities are investigating as terrorism, is the deadliest in Russia in recent years. 

Several gunmen burst into the concert hall on the edge of Moscow and sprayed visitors with automatic gunfire, killing and wounding dozens and starting a massive blaze. Russian media reported that the venue’s roof was collapsing. 

The attack comes days after President Vladimir Putin cemented his grip on the country in a highly orchestrated electoral landslide. 

There were no immediate claims of responsibility for the raid, the worst terror attack in Russia in two decades that came as the fighting in Ukraine dragged into a third year. Moscow Mayor Sergei Sobyanin described the attack as a “huge tragedy”. 

Russian news reports said that the assailants threw explosives, triggering a massive blaze at the Crocus City Hall on the western edge of Moscow. Video posted on social media showed huge plumes of black smoke rising over the building. 

There were no immediate claims of responsibility for the raid, the worst terror attack in Russia in two decades that came as the fighting in Ukraine dragged into a third year. Moscow Mayor Sergei Sobyanin described the attack as a “huge tragedy.” 

White House National Security Advisor John Kirby said that he couldn’t yet speak about all the details but that “the images are just horrible. And just hard to watch.” 

Several gunmen burst into Crocus City Hall on the edge of Moscow and sprayed visitors with automatic gunfire. Photo / AP 

“Our thoughts are going to be with the victims of this terrible, terrible shooting attack,” Kirby said. 

“There are some moms and dads and brothers and sisters and sons and daughters who haven’t gotten the news yet. This is going to be a tough day.” 

The attack took place as crowds gathered for a concert of Picnic, a famed Russian rock band, at the hall that can accommodate over 6000 people. 

Russian news reports said that visitors were being evacuated, but some said that an unspecified number of people could have been trapped by the blaze. 

- AP