People started gathering in prayer today and visiting mass graves in Aceh, one of the worst-hit areas by the Boxing Day Indian Ocean tsunami which killed an estimated 230,000 people across a dozen countries.

The tsunami was triggered by a 9.1-magnitude earthquake that struck off the west coast of North Sumatra, Indonesia, at 7.59 am local time on 26 December 2004. Indonesia suffered the highest number of deaths, but India, Sri Lanka and Thailand were also badly hit.