MOSCOW, March 26. /TASS/. Investigators are thoroughly establishing the circumstances of the barbaric terrorist attack on a crowded event at the Crocus City Hall music venue in a Moscow suburb, Russian President Vladimir Putin said.

"On March 22, dozens of our citizens were killed in a bloody terrorist attack in the Moscow Region, including children, teenagers and women. The criminals who committed this mass murder have been arrested. Investigators are carefully establishing the circumstances of this heinous crime, finding out its details, determining the role and degree of guilt of each participant, studying the conclusions of forensic scientists and experts," the head of the state said at a meeting of the board of the Prosecutor General's Office.

He added that the Federal Security Service (FSB) and other special services were also working on the case under the National Antiterrorism Committee.