Under the shade of trees at a mass grave in Indonesia's Aceh province, survivors and mourners recited Islamic prayers, commemorating the deaths of tens of thousands killed when a tsunami decimated the area two decades ago.

Emotional ceremonies began across Asia on Thursday (Dec 26) to remember the 220,000 people who died two decades ago when a tsunami devastated coastal areas around the Indian Ocean, in one of the worst natural disasters in human history.

Tearful mourners prayed Thursday as ceremonies began across Asia to remember the 220,000 people who died two decades ago when a tsunami hit coastlines around the Indian Ocean, in one