FACTBOX-What we know about the shooting at a concert venue near Moscow

Russian news agencies reported multiple casualties after a shooting incident at a concert venue near Moscow on Friday. Here's what is known about the shooting so far: -Unidentified gunmen opened fire at the Crocus City Hall in Krasnogorsk near Moscow on Friday evening during a concert of the band "Picnic", TASS reported. -The Baza news outlet, which is thought to have good contacts with Russian security services, said 18 people had died and 43 had been wounded in the attack.

Russian news agencies reported multiple casualties after a shooting incident at a concert venue near Moscow on Friday.

Here's what is known about the shooting so far: -Unidentified gunmen opened fire at the Crocus City Hall in Krasnogorsk near Moscow on Friday evening during a concert of the band "Picnic", TASS reported.

-The Baza news outlet, which is thought to have good contacts with Russian security services, said 18 people had died and 43 had been wounded in the attack. Authorities had not released an official death toll as of 1900 GMT. -The Interfax news agency reported up to five gunmen were involved in the attack.

-Russian prosecutors called the attack "an act of terrorism" and have opened a criminal case. -An eyewitness told Reuters reporters outside the venue that automatic weapons had been used.

-Video posted online by Russian news agencies showed billowing clouds of smoke and flames rising from the venue building. -TASS reported that people remained inside the building, which is almost completely engulfed in flames and that others were trapped on the roof.

-Special units of Russia's national guard as well as police and firefighters are on the scene, TASS said. -Moscow's mayor cancelled all large-scale public events over the weekend.