Seoul - South Korean prosecutors on Monday detained four more crew members in a widening investigation into a ferry disaster that left hundreds missing, presumed dead, local media reported.

Yonhap news agency cited prosecutors as saying three officers and one engineer from the capsized ferry Sewol had been taken into police custody, following the arrest at the weekend of the captain and two other crew members.

The 6,825-tonne ship sank off the southwest coast on Wednesday with 476 people on board - mostly high school students on a holiday trip.

Captain Lee Joon-Seok Lee was arrested on Saturday along with a helmsman and the ship's relatively inexperienced third officer, who was in charge of the bridge when the ship first ran into trouble.

They were charged on counts ranging from criminal negligence to violation of maritime law.

The four detained on Monday could face similar charges, the prosecutors told Yonhap. - Sapa-AFP