Local residents walk past mangled vehicles along a canal in Cagayan de Oro, on southern island of Mindnanao, on December 18, a day after tropical storm Washi wrought havoc in the city.
Philippine rescuers struggled against mud, fatigue and the stench of death on Sunday to help dazed survivors of devastating flash floods that have killed more than 500 people.
Entire villages were washed away when tropical storm Washi whipped the south on Saturday, leaving a deadly trail of flattened homes, broken bridges and upended vehicles in the poverty-stricken country.
The government and the Philippine National Red Cross appealed for help to feed, clothe and house more than 35,000 people huddled in evacuation centers as soldiers battled to recover bodies from the cloying mud.
A 20,000-strong military force has been mobilized in a huge rescue and relief operation across the stricken north coast of the island of Mindanao, where the major ports of Cagayan de Oro and Iligan were worst hit.
The Red Cross said 521 people had been confirmed dead. The number of missing had more than doubled to 370, it said, while cautioning that some of them might be among the bodies retrieved but not yet identified.
The mayor of Cagayan de Oro, Vicente Emano, said he expected the death toll to reach 500 in his city alone, which has a population of half a million.
Local freelance journalist Leonardo Vicente Corrales told AFP that fast-rotting corpses were piling up unclaimed at local mortuaries as overworked staff ran out of embalming fluid, coffins, and water to clean them.
"The bodies are decomposing too quickly because they are drowning victims -- because there is muddy water in their bodies," he said.
Amid a lack of potable water, the city government opened up fire hydrants and long lines soon formed as residents queued for fresh water, Corrales said.
Authorities likened tropical storm Washi to Ketsana, one of the country's most devastating storms which dumped huge amounts of rain on Manila and other parts of the country in 2009, leaving a death toll of more than 460.
US Secretary of State Hillary Clinton sent condolences to the Philippines and said in a statement: "The US government stands ready to assist Philippine authorities as they respond to this tragedy."
Gwendolyn Pang, secretary general of the Philippine National Red Cross, warned that many more bodies could still be found.
"We are only counting the actual dead bodies that were sent to funeral parlours," she told AFP.
"The affected area is so wide and huge and I believe they have not really gone to all areas to do a search."
Philippine President Benigno Aquino has ordered a review of the country's disaster defences amid a flurry of accounts that residents were unprepared for such a deadly storm.
Benito Ramos, executive director of the National Disaster Risk Reduction and Management Council, said the government faced a formidable task in rehabilitation and reconstruction.
The national government has begun airlifting mats, blankets and clothes to the affected populations of the south, who are being fed by local governments, he added.
Apart from those at evacuation centers -- schools, government buildings and local gymnasiums -- he said the disaster affected more than 100,000 people in one way or another who would need immediate help in rebuilding their lives.
Aquino spokesman Edwin Lacierda said the government would airlift bottled water to Cagayan de Oro.
Debris has to be cleared, electricity and drinking water have to be restored and damaged roads and bridges must be repaired, officials said.
Two army divisions -- about 20,000 soldiers -- based in Mindanao are leading the rescue and relief work. The island is the scene of a long-running insurgency led by Muslim separatists in the mainly Roman Catholic nation.
Pang said rescuers were heartened by the survivors' mental toughness.
"They are trying to rebuild. They are so resilient. Instead of all evacuating, they have gone back to their homes," she said.