The brunt of the tsunami was felt in the Indonesian province of Aceh, where 170,000 people perished. Sri Lanka, India and Thailand were devastated, too. More than a thousand miles apart, across the Indian Ocean, hundreds of coastal communities were united in their grief, and in facing years of rebuilding and regrouping.

Tearful mourners prayed on Thursday as ceremonies were held across Asia to remember the 220,000 people who were killed two decades ago when a tsunami hit coastlines around the Indian Ocean in one of the world's worst natural disasters.

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.