Two people have died and at least 295 are still unaccounted for after a ferry carrying 459 passengers and crew capsized off the south coast of South Korea on Wednesday, officials said.
The vessel listed sharply and capsized within two hours of sending a distress signal at 9.00am (00.00 GMT). Officials fear many of the missing may still be trapped in the vessel. The passengers were mostly high school students bound for the popular southern resort island of Jeju. The students and 14 teachers were from a high school in Ansan, just south of Seoul.
As the government retracted an earlier announcement that 368 people had been rescued, the Maritime Ministry said it could only confirm 164 had been brought to safety.
A ministry spokesman also said the number of passengers and crew had been revised down to 459 from the 477 initially reported. Lee Gyeong-Og, the vice minister of security and public administration, said the inflated figure for the number of rescued had resulted from confused information arriving from multiple sources.
Dramatic television aerial footage showed terrified passengers wearing life jackets clambering into inflatable boats as water lapped over the rails of the vessel as it sank.
Some could be seen sliding down the steeply inclined side of the ferry and into the water, as rescuers, including the crew of what appeared to be a small fishing boat, struggled to pull them to safety.
Many appeared to have been rescued by fishing and other commercial vessels who were first on the scene before a flotilla of coastguard and navy ships arrived, backed by helicopters.
Lee said divers, including a team of South Korean navy SEALS, were continuing to search the submerged vessel.
"There is so much mud in the sea water and the visibility is very low," he added.
The 6,825-tonne ferry, which had sailed out of the western port of Incheon on Tuesday evening, ran into trouble some 20 kilometres (13 miles) off the southern island of Byungpoong.
'A really loud noise'
The cause of the accident was not immediately clear, although rescued passengers reported the ferry coming to a sudden, shuddering halt – indicating it may have run aground.
The weather conditions were described as "fine" with moderate winds and sea swell.
"There was a really loud noise and then the boat immediately began to shift to one side," said one rescued adult passenger, Kim Song-Muk.
"People were scrambling to get to the upper decks, but it was difficult with the deck slanted over," Kim told the YTN news channel.
Photos broadcast on television showed the ship initially tilted by more than 45 degrees on the port side with helicopters flying overhead, and then fully capsized with only a small section of the stern showing above the water.
One local official who had taken a boat to the site and arrived an hour after the distress signal was sent, said he was "very concerned" about those still missing.
"The ship was already almost totally submerged when I got there. A lot of people must have been trapped," the official, who declined to be identified, told AFP by phone.
The water temperature was cold at around 12.6 degrees Celsius (55 Fahrenheit).
There were 29 crew members manning the vessel, which was also carrying 150 cars.
'We jumped into the water'
"I heard a big thumping sound and the boat suddenly started to tilt," one rescued student told YTN by telephone.
"Some of my friends fell over hard and started bleeding. We jumped into the water and got picked up by the rescue boats," he said.
Distraught parents of the students gathered at the high school in Ansan, desperate for news.
There were chaotic scenes in the school's auditorium, with parents yelling at school officials and frantically trying to make phone calls to their children.
"I talked to my daughter. She said she had been rescued along with 10 other students," one mother told the YTN news channel.
"They said they had jumped into the water before getting rescued," she said.
Scores of ferries ply the waters between the South Korean mainland and its multiple offshore islands every day, and accidents are relatively rare.
However in one of the worst incidents, nearly 300 people died when a ferry capsized off the western coast in October 1993.