The death toll in Acheh, the region worst hit by last Sunday's tsunami, may exceed 400,000 as many affected areas could still not be reached for search and rescue operations, Indonesia's Ambassador to Malaysia Drs H. Rusdihardjo said Thursday.

He said the estimate was based on air surveillance by Indonesian authorities who found no signs of life in places like Meulaboh, Pulau Simeulue and Tapak Tuan while several islands off the west coast of Sumatera had "disappeared".

He said the latest death toll of more than 40,000 in Acheh and northern Sumatera did not take into account the figures from the other areas, especially in the west of the region.

"Aerial surveillance found the town of Meulaboh completely destroyed with only one buiding standing. The building, which belonged to the military, happens to be on a hill," he told reporters after receiving RM1 million in aid for Indonesia's Tsunami Disaster Relief Fund here Thursday.

Rusdihardjo said there were about 150,000 residents in Meulaboh, which was located 150km from the epicentre of the earthquake while Pulau Simeuleu had a population of 76,000.

The death toll in Indonesia could reach 400,000, because many affected areas remain beyond the reach of rescue operations, Indonesia's ambassador to Malaysia told reporters, the Malaysia Star newspaper reported.

If the figures are correct, and the total death toll in all nations is on the order of half a million, Dec 26 will be the worst single day in human history.