Indonesia appealed for foreign aid on today as the stench of decomposing bodies underlined the urgency of its challenge after a huge earthquake that is feared to have killed thousands.
In the city of Padang which was devastated by Wednesday's 7.6-magnitude quake, the smell emanating from collapsed buildings posed health risks and indicated the official death toll of 1,100 could soar far higher.
And in the villages outside the capital of West Sumatra, survivors who have spent two nights sleeping out in the open said they were hungry and frightened, and still waiting for the first signs of government help.
"Our main problem is that there are a lot of victims still trapped in the rubble. We are struggling to pull them out," Indonesian Health Minister Siti Fadilah Supari said.
"We need help from foreign countries for evacuation efforts. We need them to provide skilled rescuers with equipment," she said, also appealing for medics to treat badly injured victims, many with broken bones.
Many countries have already pledged aid, but efforts to organise a widespread rescue operation are being hampered by blocked roads, broken power lines, and patchy communication networks.
As rescuers labour under tough conditions, in the rain and tropical heat, the chances of pulling survivors from the wreckage is fading fast.
"Looking at the situation, the chance of pulling people alive from the rubble is very slim. Their chance of survival is about 20 per cent," Indonesian Red Crescent secretary general Djazuli Ambari said.
The United Nations said in New York yesterday that 1,100 have died in the disaster. The government puts the death toll at 777, but said that figure would be revised upwards.
The first rescue flights laden with food, medicine and body bags arrived on Sumatra island yesterday and many more were expected today.
A slew of international aid organisations are already on the ground and foreign governments including Japan, Switzerland and Germany have sent specialist rescue workers and cash.
But many in the villages outside Padang, amidst scenic mist-shrouded hills, said they had not yet received any help.
"We're living in fear of another bigger quake. We're angry that no aid has come. We're hungry and we're traumatised," Ernalis, a 40-year-old resident of Parak Buruk on the edge of Padang said.
"We're living in a small tent. All our rice has been buried under the house and it's wet, we haven't eaten rice since the quake," she said.
"We are all poor farmers. We also need medicine. Some of the kids are suffering from diarrhoea."
US President Barack Obama said he was "deeply moved" by the loss of life and suffering as Washington announced $300,000 ($345,00) in immediate aid and set aside another $3 million to help quake victims.
"I know that the Indonesian people are strong and resilient and have the heart to overcome this challenge," said Mr Obama, who spent part of his childhood living in Jakarta.
At the three-star Ambacang Hotel in central Padang, manager Sarana Aji said that two events involving dozens of people were taking place when parts of the building caved in.
He was still hopeful of finding survivors, but the strong smell of decomposition indicated many have perished under the mass of pulverised concrete and steel.
"There were two big meetings going on when the quake struck. In one, there were 35 participants from the ministry of fisheries and another meeting involved 80 from Prudential insurance," Sarana Aji said.
Indonesian President Susilo Bambang Yudhoyono has sought to cast himself as in control of the disaster. His government was criticised for its response to the 2004 tsunami which killed 168,000 in Aceh province.
Dr Yudhoyono was visiting Padang today and was expected to update the media on the rescue effort.
The quake struck off Sumatra's west coast north-west of Padang, on a major fault line that scientists have long warned was a disaster waiting to happen.
A massive 9.1-magnitude quake off Aceh in northern Sumatra triggered the 2004 Indian Ocean tsunami that killed more than 220,000.
Indonesia sits on the volatile "Ring of Fire," an arc of seismic instability around the Pacific Rim.