As many as 3 gunmen dressed in camouflage clothing opened fire with automatic weapons at people in the Crocus City Hall music venue near Moscow, leaving an unknown number of people dead and injured, video footage from the scene showed.

It was not immediately clear how many people had been injured and who the gunmen were, but Russian news agencies said 50 ambulance crews had been sent to the scene.

Flames leaped into the sky and plumes of black smoke rose above the venue, video showed.

“A terrible tragedy occurred in the shopping center Crocus City today. am sorry for the loved ones of the victims. All necessary assistance would be provided to those injured during the incident”, - Moscow Mayor Sergei Sobyanin said.

Russian news agencies said police and other emergency services had arrived at the scene. Some people were still inside the concert hall.