South Korean coast guard vessels and aircraft on Sunday were searching for nine fishermen who disappeared after their boat capsized off the country’s southwestern coast.

The coast guard from the southwestern port city of Mokpo said that three crew members were rescued by a nearby commercial vessel following the accident late Saturday near Daebichi Island in the sea county of Sinan.

Survivors said the boat’s engine room had quickly filled with water before the 24-ton vessel tipped over, according to the coast guard.

Officials were planning to salvage the boat, but it wasn’t known whether the nine missing crew members would be inside. The Ministry of the Interior and Safety said seven of the missing were South Korean nationals and the two others were foreigners, but it didn’t immediately confirm their nationalities.

More than 30 coast guard vessels and at least eight coast guard and military aircraft were searching the area on Sunday afternoon.

South Korean President Yoon Suk Yeol called for officials to mobilize “all available resources” to widen the search and also to provide support to the families of the missing fishermen, his office said.