MOSCOW (AP) — Russia’s Federal Security Service says 40 people were killed and more than 100 were wounded in an attack at a Moscow concert hall.

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

The venue is still on fire and the death toll may rise.

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 reports that the venue’s roof is collapsing.

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