BANDA ACEH, Indonesia — 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.

A 9.1-magnitude earthquake off Indonesia's western tip on Dec 26,2004, generated a series of waves as high as 30 meters that pummeled the coastline of 14 countries from Indonesia to Somalia.

In Indonesia's Aceh Province, where more than 100,000 people were killed, a siren rang out at the Baiturrahman Grand Mosque to kick off a series of memorials around the region, including in Sri Lanka, India and Thailand, which the tsunami hit hours later.

People recounted harrowing tales of horror and miraculous survival as giant waves swept in without warning, carrying debris, including cars, and destroying buildings in their wake.

"I thought it was doomsday," said Hasnawati, a 54-year-old teacher who goes by one name, at the Indonesian mosque that was damaged by the tsunami.

"On a Sunday morning when our family were all laughing together, suddenly a disaster struck and everything's gone. I can't describe it with words."

At Aceh's Siron mass grave, where around 46,000 people were buried, emotional relatives recited prayers in the shade of trees that have since grown there.

The victims included many foreign tourists celebrating Christmas on the region's sun-kissed beaches, bringing the tragedy into homes around the globe.

The seabed being ripped open pushed waves at double the speed of a bullet train, crossing the Indian Ocean within hours.

In Thailand, where half of the more than 5,000 dead were foreign tourists, commemorations began early in Ban Nam Khem, its worst-hit village.

Tearful relatives laid flowers and wreaths at a curved wall in the shape of a tsunami wave with plaques bearing victims' names.

Napaporn Pakawan, 55, lost her elder sister and a niece in the tragedy.

"Time flies but time is slow in our mind."

A total of 226,408 people died as a result of the tsunami, according to EM-DAT, a global disaster database.

There was no warning of the impending tsunami, giving little time for evacuation, despite the hours-long gaps between the waves striking different continents.

But today a sophisticated network of monitoring stations has cut down warning times.

In Sri Lanka, where more than 35,000 people perished, survivors and relatives gathered to remember around 1,000 victims who died when waves derailed a passenger train.

Nearly 300 people were killed as far away as Somalia, as well as more than 100 in the Maldives and dozens in Malaysia and Myanmar, according to EM-DAT.

Agencies via Xinhua