The ocean surge was triggered by a magnitude 9.0 undersea earthquake off the Indonesian island of Sumatra, spreading in an arc of death across the Indian Ocean striking nations from Indonesia to Sri Lanka, and beyond across to Africa.

US scientists said on Tuesday the quake that set off the killer wall of water permanently moved tectonic plates beneath the Indian Ocean as much as 30 metres (98 feet), slightly shifting islands near Sumatra.

Survivors told harrowing tales of the moment the tsunami, up to 10 metres (30 feet) high, struck towns and resorts, sucking holidaymakers off beaches into the ocean, smashing people and debris through buildings, leaving more than 59,000 dead and thousands more missing and injured.

UNICEF executive director Carol Bellamy said children could account for up to a third of the dead.

"Rescuers are holding their breath while using their bare hands, axes, or shovels to dig through piles of wrecked buildings and debris at Khao Lak," said Chailert Piyorattanachote, the senior official in the Thai province.

In a further threat to the region, disease could kill as many people as those killed by the wall of water, a top World Health Organisation (WHO) official said.

"There is certainly a chance that we could have as many dying from communicable diseases as from the tsunami," the WHO's Dr David Nabarro told a news conference.

Gerhard Berz, a top risk researcher at Munich Re, the world's largest reinsurer, estimated the economic cost of the devastation at more than $13 billion.

US Secretary of State Colin Powell said the international community may have to give billions of dollars in aid.

PARADISE TURNED TO HELL

In Sri Lanka, hundreds of people were killed when a wave crashed into a train travelling to Galle from Colombo, wrecking carriages and uprooting the track it was travelling on. The train was called "Sea Queen".

In Thailand, where thousands of tourists were enjoying a Christmas break to escape the northern winter, many of the country's paradise resorts were turned into graveyards.

In a French-run hotel at Khao Lak on the Thai mainland north of the island of Phuket, up to half the 415 guests were believed killed. A reporter from France's Europe 1 radio said many bodies had been found in their rooms.

Some 136 foreign nationals and tourists were confirmed dead and 2,689 were still missing. Some 1,500 Swedes and 800 Norwegians were still unaccounted for.

Of the overall death toll so far, Indonesia has suffered the biggest number of victims, with 27,174 dead.

Nearly all the deaths in Indonesia were in the northwestern province of Aceh at the tip of Sumatra. Rescue crews were still trying to reach cut off areas. Separatist rebels announced a truce while people search for loved ones.

The stench of decomposing corpses spread over the provincial capital Banda Aceh, where fresh water, food and fuel were in short supply. Bodies lay scattered in the streets.

One of the worst hit cities was Meulaboh, about 150 km (90 miles) from the quake's epicentre. The mayor Tengku Zulkarnaen said three-quarters of his city had been washed away.

Sri Lanka reported around 19,000 dead. India's toll of 11,500 included at least 7,000 on one archipelago, the Andamans and Nicobar. On one island, the surge of water killed two-thirds of the population.

Hundreds of others died in the Maldives, Myanmar and Malaysia. The arc of water struck as far as Somalia and Kenya. Fishing villages, ports and resorts were devastated, power and communications cut and homes destroyed.

HOSPITAL LISTS

The tremor, the biggest in 40 years, ripped a chasm in the sea bed which set off the tsunami, perhaps the deadliest for hundreds of years.

A tsunami at Krakatoa in 1883 killed 36,000 and one in the south China Sea in 1782 40,000, according to the National Geophysical Data Center in the United States.

At the Thai holiday resort of Phuket, foreign tourists pored over names on hospital lists and peered at 80 hospital photos of swollen, unidentified bodies.

"My father was not there," said German yacht skipper Jerzy Chojnowski, who was looking for his 83-year-old father, missing since the tsunami struck. "My father was not a good swimmer."