The security forces stormed the Crocus City venue in Moscow following the attack. There are reports that terrorists have barricaded themselves, and also reports that some may have left.

"A search is underway for four men in camouflage clothing who may have fled the crime scene."

The "Siren" security plan has been introduced in Moscow, police personnel are being assembled for reinforcements.

Sobyanin said that he had decided to cancel all sports, cultural and other public events in Moscow this weekend.

At least 40 people were killed and more than 100 were injured as a result of the shooting at Crocus City Hall.

The building continues to burn. The fire area is about 3000 square meters.