Across the region, stories of incredible devastation emerged as one of the largest and most complex relief efforts ever undertaken swung into action.

The worst-hit area appeared to be the Aceh province of Sumatra, where one town alone, Meulaboh, reported 10,000 dead. The Indonesian government put the death toll in the country at more than 27,000, with another 1,000 missing. Some towns still have not been heard from, and elsewhere many bodies remain buried under rubble and mud.

India’s death toll of 11,500 included at least 7,000 on the Andamans and Nicobar archipelago. On one island, the surge of water triggered by Sunday’s undersea earthquake killed two-thirds of the population.

The government of the Maldives expressed concern that it still had not heard from 19 inhabited islands and said there was a real danger some of its low-lying islands could be lost forever. British disaster assessment experts were on standby last night to fly there.

In Thailand, where more than 1,500 people died, government meteorology officials admitted they deliberately played down the expected impact of the earthquake to protect the country’s tourist industry.

Rescue workers there yesterday recovered more than 300 bodies on the country’s remote Phi Phi island, made famous by the film The Beach, starring Leonardo DiCaprio. Bloated bodies were washed ashore as hopes of finding survivors in the wrecked seafront hotels and shops faded.

1,700 dead in train smash

In Sri Lanka, as many as 1,700 passengers crammed in a train destined for the southern city of Galle were feared dead after a wave swept carriages off the rails and filled them with water. More than 18,000 people were reported dead in the island.

But the emerging picture of devastation was not confined to the immediate environs of the quake’s epicentre off Sumatra. Communities were devastated as far away as the coast of Somalia in eastern Africa, almost 5,000km away. Lives were also lost in Kenya, the Seychelles, Tanzania, Bangladesh, Malaysia and Burma.

Seventeen Britons have been confirmed dead, 10 in Thailand, four in Sri Lanka and three in the Maldives. Among them was film director Lord Attenborough’s 14-year-old grand daughter, Lucy. His daughter, Jane, and her mother-in-law were missing feared dead. A six-year-old boy from St Ives on holiday with his family in Thailand was another confirmed as dead.

Danger of epidemic

The World Health Organisation said the focus now should be on preventing the spread of disease, especially malaria and cholera. Dr David Nabarro, head of crisis operations for the WHO, said: "There is certainly a chance that we could have as many dying from communicable diseases as from the tsunami."

Dr Nabarro said the main threat was diseases associated with a lack of clean water and sanitation. It was also a possibility that diseases like pneumonia could sweep through encampments of homeless people. Hospitals and health services were already overwhelmed and may not be able to cope with people who fall ill with disease, he warned.

Aid and relief workers have begun to reach the stricken region and pressure is growing on the United Nations to take a strong lead in ensuring that the right supplies reach the most needy survivors. The picture is complicated because the disaster stretches across so many countries and such a wide region.

Louis Michel, the EU commissioner responsible for humanitarian aid, called for international donors to hold an urgent conference to coordinate aid.

He said: "I am very anxious about the linkage between the emergency phase and the second phase of rehabilitation and reconstruction. If there is a gap between the two phases, I think it will have catastrophic consequences."