There was a loud impact and noise before the ferry off a coast of South Korea began sinking, a passenger who had been rescued from the vessel told YTN news television.
One person has been found dead in the ferry wreckage, according to a coast guard official.
The president of South Korea, Park Geun-hye, earlier ordered all available vessels and special operations divers to the rescue operation.
More top news
Lucy Beale's killer will be revealed live on air during a special week of EastEnders episodes to mark the soap's 30th anniversary.
Spandau Ballet reunited on stage for the first time in five years as the band performed at the premiere of a film documenting their career.
From tomorrow, tax discs will no longer be needed to show drivers have paid their vehicle tax. Richard Pallot reports on the end of an era.