Indonesians have commemorated the 18th anniversary of the deadly Indian Ocean tsunami that struck on December 26, 2004. The disaster left more than 220,000 people dead or missing in a vast area spanning from Southeast Asia to East Africa.

The tsunami was triggered by a massive earthquake that struck off the coast of Indonesia's Sumatra Island. More than 160,000 people were killed in Aceh province, located on the northwest tip of the island.

A memorial ceremony was held on Monday at a cemetery in Aceh. Prayers were offered at 8 a.m., around the time the earthquake struck. Police and military officials scattered flower petals on the ground to mourn the victims.

Local residents staged a play, reenacting the devastation wrought by the surging tides.

A 64-year-old man, whose parents remain missing, recalled that the tsunami turned the town into a hellish landscape. He said some people think that a major tsunami will only occur once in 300 years, but he believes one could strike again at any time.

A 17-year-old girl said she was never taught at school about the disaster or how to prepare for one. She said young people should reach out to one another and learn more about natural disasters.