A top investigator says a sailor set off the fire safety system on a Russian nuclear submarine last weekend that killed 20 people.
Investigative Committee spokesman Vladimir Markin says officials have opened a manslaughter investigation into the actions of the unnamed sailor, who he says confessed to the act. He gave no further details Thursday.
The announcement contradicts previous official statements that the fire-extinguishing system aboard the Nerpa had gone off on its own.
The Nerpa was undergoing tests Saturday in the Sea of Japan when its firefighting system activated. Freon gas asphyxiated 20 people on the sub and 21 were hospitalized.