Thousands of people held a memorial Thursday in Indonesia's Aceh province, the epicentre of the Indian Ocean tsunami, as the world prepared to mark a decade since a disaster that took 220,00 lives and laid waste to coastal areas in 14 countries.

On December 26, 2004 a 9.3-magnitude earthquake off Indonesia's western coast sparked a series of towering waves that wrought destruction across countries as far apart as Indonesia, Thailand, Sri Lanka and Somalia.

Among the victims were thousands of foreign holidaymakers enjoying Christmas on the region's sun-kissed beaches, striking tragedy into homes around the world.

Muslim clerics, tsunami survivors and rescue workers led around 7,000 mourners gathered at Banda Aceh's black-domed Baiturrahman Grand Mosque for memorial prayers late Thursday.

Malaysian cleric Syeikh Ismail Kassim said he and several hundred compatriots attended to show support for Aceh.

"We hope Aceh people will not waver as a result of the calamity that has befallen them," he told AFP.

Aceh governor Zaini Abdullah thanked Indonesians and the international community in his address at the mosque, one of the few buildings which withstood the wrath of the massive earthquake and ensuing waves which left 170,000 people in the country dead or missing.

"The tsunami had caused deep sorrow to Aceh residents from having lost their loved ones," he said.

"Sympathy from Indonesians and the international community has helped (Aceh) to recover," he added.

He also called on residents not to "dwell in our grief, so that we could rise from adversity and achieve a better Aceh".

Kamaruddin, a fisherman who like many Indonesians goes by one name, said he attended the prayers to remember his wife and three children who died in the tsunami.

"I hope there will be no more disasters in Aceh," the 50-year-old said.

In Meulaboh, a fishing town considered to be the ground zero of the tsunami -- where 35 metre-high waves flattened almost everything -- Indonesian flags were flown at half-mast as small groups of residents held night prayers at mosques.

The main memorials were planned for Friday morning, starting in Aceh which was hit first by the waves, then moving to Thailand where candlelit ceremonies are expected in the resort hubs of Phuket and Khao Lak.

There will also be events in Sri Lanka, including at the site where a train carrying 1,500 people was washed away, as well as in several European capitals to remember foreign nationals who perished.

- 'Like being in a washing machine' -

Many of the tsunami's victims died in dark, churning waters laden with uprooted trees, boats, cars and eviscerated beach bungalows, as the waves surged miles inland and then retreated, sucking many more into the sea.

Thailand saw 5,395 people killed by the disaster -- half of them foreign holidaymakers.

British survivor Andy Chaggar was in a bungalow on Thailand's Khao Lak when the tsunami waves struck, taking his girlfriend's life and sweeping him inland.

"I came to in the water... there was glass, metal, there were pieces of wood, bricks, it was like being in a washing machine full of nails," he told AFP on Thursday, on the same beach where he lost his girlfriend.

As the scale of the tragedy emerged, disaster-stricken nations struggled to mobilise a relief effort, leaving bloated bodies to pile up under the tropical sun or in makeshift morgues.

The world poured money and expertise into the relief and reconstruction, with more than $13.5 billion collected in the months after the disaster.

Almost $7 billion in aid went into rebuilding more than 140,000 houses across Aceh, thousands of kilometres of roads, and new schools and hospitals.

The vast majority of Indonesia's 170,000 victims perished in the province, among them tens of thousands of children.

But the disaster also ended a decades-long separatist conflict, with a peace deal between rebels and Jakarta struck less than a year later.

It also prompted the establishment of a pan-ocean tsunami warning system, made up of sea gauges and buoys, while individual countries have invested heavily in disaster preparedness.

But experts have cautioned against the perils of "disaster amnesia" creeping into communities vulnerable to natural disasters.

Sri Lanka train guard mourns tsunami dead 10 years on
Colombo (AFP) Dec 26, 2014 - Wanigaratne Karunatilleke knew nothing about tsunamis before a wave of water slammed into his train on the Sri Lankan coast a decade ago, killing more than a thousand people.

With a little more knowledge, the 58-year-old train guard now believes he could have helped the victims of Sri Lanka's worst tragedy escape to safety.

Karunatilleke was among the few survivors of the disaster on the Ocean Queen Express, which has become a symbol of the disaster in Sri Lanka, and will be at the centre of commemorations for the country's 31,000 victims on Friday.

Shortly before the tsunami hit, he says, the train was brought to an abrupt halt by a wave just after Kahawa station, 90 kilometres (56 miles) south of the capital Colombo.

He believes the 15-minute lull that followed could have allowed passengers to escape to high ground, and blames the huge loss of life on a lack of knowledge about tsunamis.

"If I had known about tsunamis," Karunatilleke told AFP in an interview.

"We had about 15 minutes to move the passengers to safety. I could have done it. We had the time, but not the knowledge."

Karunatilleke, who as head guard was responsible for passengers' safety, overruled the signalling system after the first wave and ordered the driver to move, but by then it was too late.

When the tsunami hit, he became trapped inside a compartment that was floating in the water, managing to escape through a window.

The train was rebuilt after the tsunami and since then Karunatilleke, who is still head guard, stops at the exact same spot every year on December 26 to pay his respects to his departed passengers.

This year will be particularly significant, with the Colombo to Matara train making a special journey for passengers to attend Buddhist, Hindu, Christian and Muslim ceremonies planned to mark the 10th anniversary of the disaster.

The tsunami wave first hit Sri Lanka's southeastern coast, travelling across the island at an average speed of about 500 kilometres (300 miles) an hour and killing 31,000 people in a single hour.

Sri Lanka had not been hit by a tsunami in living memory before 2004 and the tragedy became the country's worst natural disaster.

The memories still haunt Karunatilleke, who recalls rescuing a small girl and boy from the floodwaters and placing them inside a train compartment only to see it smashed minutes later.

"I will remember those two children for the rest of my life" he said.

"I did not know about tsunamis then and neither did anyone else on board.

"I wish I had known.... I really feel bad that I was not able to save those lives."