JINDO, South Korea (AFP) - South Korean prosecutors sought arrest warrants on Friday for the captain and two crew members of the ferry that capsized two days before with hundreds of children on board, a coast guard official said.

"The joint investigation team of police and prosecutors asked for warrants to arrest three crew, including the captain," the official in the southern coast guard headquarters in Makpo told AFP.

The request was submitted to the local court, he said, while adding that he was unaware of the precise charges.

The captain and most of his 28 crew managed to escape the ferry, and have been criticised for abandoning the ship when so many were still trapped on board.

Tracking data from the Maritime Ministry showed the ferry made a sharp turn just before sending its first distress signal on Wednesday morning.

Some experts believe such a tight turn could have dislodged the heavy cargo manifest - including more than 150 vehicles - and destabilised the vessel, causing it to list heavily and then capsize.

But others suggested the turn might have been caused by a collision with a rock or other submerged object.

Prosecutors said Friday that preliminary investigations showed that Captain Lee Joon Seok had handed the helm to his third officer before the ferry capsized.

Lee apologised Thursday to the victims and their relatives, but offered no clear explanation for what caused the ship to go down.

"I feel really sorry for the passengers, victims and families," Capt Lee said. "I feel ashamed."