Seoul: One person has been found dead in a South Korean ferry that is sinking off the southwest coast, a coast guard official said on Wednesday.

As the rescue continues, South Korea's president Park Geun-hye has ordered all available vessels and special operations divers to assist with the operation.

A South Korean passenger ship, with more than 400 passengers on board, is seen listing heavily in the sea off Jindo. One passenger said those on board were in their cabins but having trouble keeping their balance. Credit:Reuters

The car ferry 'Sewol' was carrying 447 people, many of them students on the way to Jeju island, when the ship appeared to run into something and began to list heavily.

There was a loud impact and noise before the ferry started sinking, a passenger who had been rescued from the vessel told YTN news television. Another passenger on board had earlier told YTN a rescue helicopter had reached the vessel. The unidentified passenger, who sounded calm, said those on board were in their cabins but were having trouble keeping their balance.