President Vladimir Putin fired the head of Russia's navy Sunday and called on the new commander to boost discipline in the flagging fleet following a pair of submarine accidents.

Putin did not give a specific reason for dismissing Adm. Vladimir Kuroyedov and replacing him with Adm. Vladimir Masorin. But he indicated that Kuroyedov was bearing the blame for a series of embarrassments to the navy.

Last month, a mini-sub with seven men aboard was trapped at the bottom of the Pacific Ocean. The navy had no means of rescuing them without help from abroad.

Kuroyedov also presided over the navy during the 2000 Kursk submarine sinking that killed all 118 crew members. Last year, he said publicly that a Russian nuclear-powered missile cruiser was in such dire condition that it could explode at any moment. He was forced to retract the statement.

At a meeting at his suburban residence with the two admirals and Defense Minister Sergei Ivanov, Putin told Kuroyedov that the navy he inherited when he took command in 1997 was in poor shape and that it had showed signs of improvement.

"At the same time, there were difficult events, tragedies," Putin said. "But I would like to underline once again that with all these problems, all these tragedies, the main thing is that the navy is undergoing a revival."