Six aid organisations have issued a new appeal for funds to help survivors of last month's earthquake in Indonesia.
Agencies say 1.5 million people could be homeless
Relief operations are "hamstrung because of a lack of funds from donors", the agencies said in a joint statement.
David MacDonald of Oxfam said that the scale of the disaster was much greater than originally thought.
The Indonesian government has estimated that up to 1.5 million people have been left homeless.
It puts the number of homes destroyed at 156,964, with another 183,741 homes severely damaged, the statement said. The figure of 1.5 million people is based on an average of five people per house.
"The number of homeless people and extent of the damage is higher than after the 2004 tsunami in Indonesia," said Johan Kieft, emergency response team leader for CARE Indonesia.
The statement comes from Oxfam International, Islamic Relief, World Vision, CARE Indonesia, CARDI/IRC and Plan International.
People are in urgent need of shelter
The UN said on 1 June said more than $100m (£54m) would be needed for relief work over the next six months. Only $21m of that had been promised so far, the statement said.
"Donors responded swiftly in the initial stages," says Mr MacDonald, country programme manager for Oxfam Indonesia, "but now we need them to evaluate their commitments to reflect ongoing urgent needs for the basics such as shelter, water and sanitation."
Oxfam spokesman in Yogyakarta Harriet Binet confirmed that estimates of those left homeless had risen dramatically.
"In the early days, there wasn't accurate assessment and evaluation done by appropriate authorities," she told the BBC. This was because officials were focusing on the immediate relief effort, she said.
"We are looking at a totally different scenario now," she said.
More than 5,700 people died in the earthquake that hit central Java province on 27 May, according to the latest Indonesian government estimates.