Maritime police search for two missing sailors after a fishing boat incident in waters off Korea's southwestern coast, Thursday. Courtesy of Mokpo Coast Guard

A fishing boat carrying nine people capsized in waters off Korea's southwestern coast early Thursday, leaving its Korean captain dead and two Indonesian sailors missing.

According to the Coast Guard, the 33-ton eel fishing trawler was overturned at around 3:18 a.m. in waters some 18km northeast of Gageo Island off Mokpo, a port city in South Jeolla Province.

Six of the crew members were rescued by fishing boats working nearby. But the captain had already died by then.

The Coast Guard is now searching for the missing sailors in collaboration with the Navy and fishermen. Several ships, airplanes as well as fishing boats have joined the rescue effort.

Based on survivors' accounts, the Coast Guard suspects that a collision with another fishing boat was the cause of the accident.

The crew of the other boat allegedly involved in the collision have been questioned as the Coast Guard looks into the case.