The number of people killed in the earthquake which hit the island of Java on Saturday has increased to more than 6,200, Indonesian authorities say.
Medical help is getting through but hospitals are still struggling
At least 30,000 people have been injured and more than 105,000 homes destroyed or damaged, leaving hundreds of thousands of people displaced.
However, authorities say they expect the figures to rise as further damage assessment is carried out.
The UN says aid is now getting through to most areas.
But a UN official said hospitals were struggling to cope with the numbers of injured.
"Most of the hospitals are functioning, but are overloaded. There is a lack of space in the hospitals," Charlie Higgins, the UN's humanitarian co-ordinator in Yogyakarta, the city worst affected by the disaster, told AFP news agency.
"It's getting out the basic medical supplies to the hospitals that is important," he said.
As hospitals remain overcrowded and delivery of aid has been hampered by bad weather, some locals have been forced to spend a fifth night without shelter.
A field hospital set up by the US in Sewon, south of Yogyakarta, is expected to become fully operational on Thursday.
The UN's top humanitarian co-ordinator, Jan Egeland, was optimistic about the aid effort.
"Of course there are villages and people who have not yet got assistance because there are hundreds of thousands of severely affected people in a big area and we're less than a week into the emergency."
"I think the Indonesia system works. It has been working very well," he said.
President Susilo Bambang Yudhoyono, who spent four days in the region, said he had enough confidence in the relief efforts to return to the capital, Jakarta.
The 6.3 magnitude quake hit the ancient city of Yogyakarta early on Saturday.
The region is close to the volcano Mount Merapi which has been spewing lava and ash for some weeks.
The Asian Development Bank has promised $60m (£32m) in aid and loans to help the affected region.
The Indonesian government has pledged an initial 12kg of rice per family, and 200,000 rupiah ($21) for each survivor to cover clothing and household goods, and compensation for damaged houses.