Authorities in Russia say several gunmen have opened fire at a concert hall on the outskirts of Moscow. They say at least 40 people are dead, and more than 100 others injured.

The Islamic State militant group has reportedly claimed responsibility.

The incident took place on Friday evening in the city of Krasnogorsk. Russia's federal security service is calling it a terrorist attack.

Authorities say several people wearing camouflage stormed the venue before a concert.

State-run television aired footage of flames and smoke billowing from the building.

Government officials say more than 320 workers are battling the fire and engaged in rescue operations.

The RIA Novosti news agency says at least three people were involved in the shooting, adding that there are reports of explosives being thrown.

Security forces are searching for the shooters.

Kremlin spokesperson Dmitry Peskov told local media that President Vladimir Putin was immediately informed of the attack, and has since been giving all essential instructions.