Disaster official Ade Edward says the 3m (10ft) surge is likely to have carried many of the missing out to sea, or buried them in the sand.

The first major aid ships reached the worst-hit Mentawai Islands on October 29. The government has pledged millions of dollars for the relief effort, but activists say more needs to be done.

Aid agencies said people on the islands still urgently needed to food and shelter, three days after a 7.7-magnitude undersea earthquake triggered the tsunami.

Indonesia is also struggling with the devastation caused by this week's eruption of Mount Merapi in central Java, which killed more than 30 people.

As the scale of the tsunami disaster became clear on October 29, Mr Edward painted a bleak picture of the chances of finding more survivors.

"Of those missing people we think two-thirds of them are probably dead, either swept out to sea or buried in the sand," he told the AFP news agency. He estimated that a further 200 people may have been killed.

Indonesia's state-run news agency Antara reported that 468 houses had been completely destroyed by the wave.