Tropical storm Washi whipped the southern Philippines, unleashing mammoth floods across vast areas that left 440 people dead and nearly 200 missing, relief workers said on Saturday.
About 20,000 soldiers had been mobilised 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.
Cagayan de Oro city reported 215 dead, and nearby Iligan city lost 144 residents, Philippine National Red Cross secretary-general Gwen Pang told AFP.
Iligan mayor Lawrence Cruz described rampaging floodwaters from swollen rivers that swamped up to a quarter of the land area of the city of 100,000.
"It's the worst flood in the history of our city," Cruz told GMA television. "It happened so fast, at a time when people were fast asleep."
The station showed dramatic pictures of a family escaping out of the window of their home in the town as the floods rose, and rescue workers in orange vests shepherding survivors to safety above chest-deep waters.
"Most of them were asleep as floodwaters rushed down at 2:30am (1830 GMT Friday)," Benito Ramos, head of the National Disaster Risk Reduction and Management Council told reporters in Manila, referring to the victims.
"They were warned (about the approaching storm), but they did not go into preemptive evacuation."
He said Mindanao was rarely visited by storms, although about 20 major storms strike the Philippines annually, with most hitting Luzon, the largest and most populous island in the Southeast Asian archipelago.
"We expect huge damage, especially on agriculture," Ramos said.
Marlyn Manos, an Iligan resident, recounted how she and her children watched in terror from their rooftop as the floodwaters swallowed up the neighbourhood.
"All the small houses behind ours were destroyed, and many of my neighbours are missing," she said.
Iligan tourism officer Pat Noel told AFP waters began rising shortly before midnight (1600 GMT Friday) as people slept, sweeping houses made of light materials and their inhabitants along the riverbanks.
"Many of them told me they sought refuge on their rooftops," he said after joining the first wave of rescuers at daybreak.
Two of the three rivers that flow into the port of Iligan had overflowed, he added, and a popular radio commentator was among those killed.
Other affected areas on Mindanao included Bukidnon province, where 47 people died, while nine others people were killed elsewhere on the island, Pang of the Red Cross said.
Twenty-five people meanwhile drowned on the island of Negros, the provincial civil defence office told AFP.
Pang said 162 people were still missing in Cagayan de Oro and Iligan, while a Negros official said 19 people were missing there.
President Benigno Aquino has ordered 10 evacuation centres to be put up in the affected areas of Mindanao, his spokeswoman Abigail Valte said on government radio.
The western island of Palawan is expected to be hit on Saturday night with slightly weakened peak winds of 65 miles (46.4 miles) after Washi crosses the Sulu Sea, the state weather service said.