Two U.S. sailors died Friday when waves knocked them from the deck of a nuclear submarine off the coast of southwestern England.

Two other sailors were injured.

The four menwere working on the outer casing of the USS Minneapolis-St. Paulinbad weather when they were thrown off the deck, the British Broadcasting Corporation reported Friday.

The menwerein safety harnesses, but could not hoist themselves back on the deck of the 110-metre submarine.

"They were tied on but getting battered about by the weather," a spokesperson for the Brixham Coast Guard told the BBC.

The BBC saida helicopter, tug boat and lifeboat were used to rescue the men. Two were having trouble breathing when they were found andwere givenCPR. They were pronounced dead at a hospital in Plymouth.

The two other men were treated and released.

The submarine was just pulling out of the Devonport naval base when the accident occurred, said the BBC.

The submarine, which is based in Norfolk, Virginia, had been in Plymouth for a week. The British Ministry of Defence would not say why the vessel was in British waters.

The names of the sailors were not released Friday.

With files from the Associated Press