US Navy joins search for missing S.Korean sailors

Four US Navy ships are joining a search and rescue operation for dozens of South Korean sailors who are missing and possibly trapped aboard a vessel that exploded and sank near the disputed sea border with North Korea.

A spokesman for the US 7th Fleet, which is based just south of Tokyo, said the four ships were already in the area for military exercises and joined the rescue mission on Monday after getting a request from Seoul for assistance.

Forty-six sailors are believed trapped inside the South Korean military ship that sank late Friday due to an unexplained explosion. South Korean and US officials say they have no indication of North Korean involvement.