More than 280 people are still missing after a ferry carrying 462 people, mostly high school students, sank off South Korea's southern coast.

Only four people have been confirmed dead so far, but the high number of people unaccounted for suggests that the death toll could rise drastically.

The students on the Sewol ferry were on their way to Jeju island for a four-day trip. Most were in their second year of high school, which would make them 16 or 17.