More than 20 people have been killed in an accident on a Russian nuclear submarine, local media reported on early Sunday.

"Over 20 people have been killed on Nov. 8, as a result of accidental activation of the fire extinguishing system at a nuclear-powered submarine of the Pacific Fleet during sea trials," Itar-Tass cited a navy spokesman.

Russian seamen line up on an unidentified submarine believed to be an Akula-class submarine during a military parade training in Vladivostok in this July 25, 2008 file photo.