South Korean coast guard ships and aircraft are searching for nine fishermen who went missing after their boat capsized off the country's southwest coast.

After the accident, which happened last night near the island of Debichi, three crew members were rescued by a commercial vessel that was nearby, the coast guard of the southwestern city of Mokpo said.

Survivors said that the engine room of the ship filled with water very quickly, and then the 24-ton ship capsized.

American media quoted the Ministry of Internal Affairs and Security as saying that seven of the missing are South Korean citizens and the remaining two are foreigners, but did not specify their nationalities.

Today, more than 30 coast guard ships and at least eight aircraft are actively involved in the search for the missing.

The South Korean president Yun Suk-Yol urged authorities to mobilize "all available resources" to expand the search, as well as provide support to the families of the missing fishermen, his office said.