A passenger was stabbed to death on the Lyublinsko-Dmitrovskaya Line line near the Dubrovka metro station, police said Tuesday.
At about 11 p.m. Monday night an unidentified attacker stabbed a 28-year-old man inside an outbound train as it approached the Dubrovka station and then fled, the Investigative Committee said in a statement.
Investigators said the victim received "at least six wounds in the chest, stomach and left hip" and later died on the way to the hospital.
Earlier reports mentioned two attackers and said the man was stabbed at the station, RIA-Novosti said.
Investigators opened a criminal case on charges of murder, which are punishable by up 15 years in prison.