Nine fishermen are missing after a boat capsized off the southwestern coast of South Korea late Saturday, authorities said. 

On Sunday, more than 30 coast guard vessels and at least eight coast guard and military aircraft were searching for the missing fishermen. Three crew members have been rescued near a commercial vessel following Saturday night’s accident.

Survivors said the boat's engine room had quickly filled with water before the 24-ton vessel tipped over near Daebichi Island in the sea county of Sinan, according to the coast guard.

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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. 

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

The Associated Press contributed to this report.