When a 9.15-maAsia remembers devastating 2004gnitude quake opened a fault line deep beneath the ocean on Dec. 26 a decade ago, it triggered a wave as high as 17.4 meters (57 feet) which crashed ashore in more than a dozen countries, wiping some communities off the map in seconds.

Memorials were held in the worst-affected countries - India, Thailand, Sri Lanka and Indonesia - where monks, imams and priests held ceremonies to honor those who perished.

Hundreds gathered in Indonesia's Aceh province, many bursting into tears as poems and songs were heard and a montage was screened showing the devastation from a disaster that killed 126,741 people in Aceh alone.

"It seems there's no bigger lesson to Aceh than this. It is as if the souls of the dead are still with us," said provincial governor Zaini Abdullah, formerly a prominent figure in a long-running separatist conflict the tsunami helped end.

Vice President Jusuf Kalla said the memorial brought him to tears but he took solace in a peace deal that proved adversity could bring people together to reconcile differences.

Mass prayers were held late on Thursday at Banda Aceh's Grand Mosque, one of a few buildings that withstood the waves

"Allah kept his house unscathed, that's what we Muslims believe," said Azman Ismail, the Great Imam of the Masjid Baiturrahman mosque.

Relatives of victims also prayed at the graves of loved ones in Hambantota, Sri Lanka, where 677 Muslim families were relocated after the tsunami destroyed their village. Some 40,000 people were killed in Sri Lanka, but heavy rain in Hambantota forced the cancellation of memorial events there on Friday.

Fisherman Tuan Ilyas Idrees, who lost 10 family members, was deep in prayer after finding his dead mother's grave close to a coconut tree by a mosque.

Idrees tearfully said his entire village was wiped out.

"I ran to my house to save my mother and others, but in just five minutes, there was no house at all," Idrees said.

"We buried hundreds of bodies."

The restored train Samudra Devi, or "Ocean Queen", made a special journey in Sri Lanka on Friday in memory of the 1,270 people killed when it was thrown off its rails by the waves.

Big crowds also gathered and laid wreaths at Thailand's tsunami memorial park in Ban Nam Khem, a fishing village destroyed by the waves. Family members wiped away tears as they placed flowers next to a remembrance wall with a plate bearing the names of those who died.

"The great loss at that time is a reminder for everyone to be prepared for natural disasters," Thai Prime Minister Prayuth Chan-ocha said at an evening memorial in Phang Nga province, where 80 percent of Thailand's tsunami victims died.

Some 5,395 people were killed in Thailand, among them about 2,000 foreign tourists. Swedish policemen visited graves of some of the more than 300 unidentified victims. Almost 3,000 people remain missing.

A decade ago experts from 39 nations gathered in Thailand to identify bodies in what became the world's biggest international forensics investigation. About 700 people carrying flowers and banners marched from the beach where the wave smashed against India's southern Tamil Nadu coast to a black granite memorial, stopping by a Christian shrine to pray for the dead.

In coastal districts of Tamil Nadu, shops were closed and many fishermen stayed ashore as a mark of respect for the 6,000 who died there while Christian hymns were sung and verses read from the Koran and Hindu texts at an inter-faith ceremony.

An Acehnese man cries while praying for a tsunami victim at a mass graveyard in Banda Aceh

Illaycha, who lost five children, was inconsolable as she lit a candle. "I'm praying to the gods that they should take care of them in heaven," she said.

Tsunami escape drills were to be held to demonstrate the readiness of Tamil Nadu's large fishing community.

But doubts linger about how ready countries on the Indian Ocean really are for another giant wave. The past decade has seen more than $400 million spent across 28 countries on an early-warning system comprising 101 sea-level gauges, 148 seismometers and nine buoys, but there is concern about the effectiveness and maintenance of the system.

Some experts say complacency is leaving millions vulnerable and governments still warn of the ever-present risks.

Thai Interior Minister Anupong Paochinda said it was crucial people were better informed and early warning systems functioned fully, while Aceh's governor said lessons must be learned.

"We have to prepare when disaster comes, so we can mitigate it fast and right," Abdullah said.