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. More than 20 people were killed and another 21 injured in an accident aboard a Russian nuclear submarine in the Pacific Ocean, the navy said on Sunday, in the worst submarine disaster since the Kursk sank eight years ago. The RIA agency quoted a source in the Amur Shipbuilding Enterprise as saying the accident occurred aboard the Nerpa, a Project 971 Shchuka-B attack submarine, known inside NATO as an Akula-class submarine. Picture taken July 25, 2008. REUTERS/Yuri Maltsev (RUSSIA)
REUTERS/STRINGER/RUSSIA