Aid workers around the Indian Ocean are struggling to reach millions affected by Sunday's devastating tsunami waves.
The hunt for survivors is drawing to a close
Relief teams and supplies are pouring into the region but have yet to reach the hardest-hit and most remote areas.
There are reports of desperate people fighting over aid. Aftershocks and fears of new tsunamis have sown panic among survivors in Indonesia and India.
Millions remain at risk from hunger and disease five days after the disaster, now known to have killed 84,000 people.
The US, Australia, Japan and India have formed a coalition to provide relief.
Foreign governments have pledged more than $220m in aid - $35m of which is promised by the US.
But the UN's relief co-ordinator, Jan Egeland, has said it will take another "two or three days" for the relief effort to get into full swing - by which time it may be too late for tens of thousands of people.
"We are doing very little at the moment," he said.
"I believe the frustration will be growing in the days and weeks ahead."
Anger is building among survivors in the Indonesian province of Aceh, near the epicentre of Sunday's earthquake.
"There is no food here whatsoever. We need rice. We need medicine. I haven't eaten in two days," a local woman told Reuters news agency.
The BBC's Andrew Harding in Banda Aceh says relief supplies are barely trickling into the city where drinking water is also scarce and corpses clog the streets.
There are reports of fighting among survivors over food aid in the city.
Thousands of survivors, broken by their loss, face new dangers
A lone airport serves the entire region and road links to many remote areas have been washed away by sea waters.
Efforts are also being hampered by a petrol shortage and damage to port facilities.
Indonesia's navy has sent ships to isolated communities on the west coast of Sumatra but the picture there remains unclear.
On Thursday, aftershocks off Indonesia triggered fresh panic among survivors in Aceh.
Rumours of impending waves quickly spread to the two other countries which bore the brunt of Sunday's tsunamis - India and Sri Lanka.
Indian officials issued a warning, prompting many people to flee coastal areas both in southern India and Sri Lanka.
Across the region thousands remain unaccounted for since the 9.0 magnitude undersea earthquake off Sumatra that forced a wall of water smashing into coastlines as far away as east Africa.
There are fears that epidemics will erupt because water supplies have been contaminated.
KEY AID PLEDGES
Saudi Arabia: $10m
Source: Reuters, United Nations
The Red Cross says the eventual death toll may reach over 100,000.
The UN has said it is set to issue what may be its largest-ever appeal for aid.
The US is sending two aircraft carriers and other ships to the region. It is also using its spy satellites to assess damage to roads, bridges, ports and airfields.
The head of the World Health Organization's crisis team, David Nabarro, says as many as five million people cannot get water, food or adequate sanitation.
International aid is beginning to arrive at some of the worst-hit areas along Sri Lanka's southern and eastern coast, says the BBC's Gina Wilkinson in Galle.
The priority, she says, is to prevent an outbreak of water-borne disease amid the hot and humid conditions.
IMPACT OF THE EARTHQUAKE