A fishing boat carrying 11 people sank off the country's south coast Thursday, leaving three dead and another missing, the Coast Guard said.

Four South Korean and seven foreign crew members were aboard the 139-ton trawler when it sank in waters 4.6 nautical miles south of Yokji Island off the coastal city of Tongyeong, some 330 km south of Seoul, after sending a distress call at 4:12 a.m., the Coast Guard said.

Ten crew members were rescued by the Coast Guard and nearby boats, including three Koreans who were found unconscious. The three, including the captain of the boat, were taken to a hospital but later pronounced dead.

The seven foreigners who were rescued, including six Indonesians and one Vietnamese, sustained non-life threatening injuries, according to authorities.

The fishing boat was returning from work after it departed from the Dongho port on the southern coast of Tongyeong at 5:10 p.m. the previous day.

The Coast Guard is conducting search operations to find the last remaining Korean sailor using 16 Coast Guard ships, two naval vessels, two ships dispatched from a related institution and three aircraft.

The ship has completely submerged, according to authorities. The waters where the accident took place are estimated to be 60 meters deep. (Yonhap)