The most severely affected area was the town of Subic, about 80 kilometers northwest of Manila. Heavy rains there caused rain-soaked soil to cascade down, killing six people, said town mayor Jay Khonghun. (Agencies)
"We've been experiencing very heavy rain. We are now isolated. I can confirm there are two landslide incidents here. Six people were so far killed," Khonghun said.
"The flood water is chest-deep in many areas, and the rain is pounding and the water keeps on rising," he said.
It is not clear how many people have been left stranded in the town of 160,000, but one resident reported that "many" people were waiting on rooftops for rescuers.
Government employee Cristina Humbert, 35, said the ground floor of her two-storey home had been flooded but she managed to evacuate her 63-year-old mother to higher ground.
"Many are on the rooftops, waiting for help. They are marooned, and are getting hungry and cold. We have no power, no electricity," she said.
Khonghun said four rivers that pass through Subic were heavily silted and had overflowed, causing the floods. He called on the national government to come to the town's aid.
"We are appealing for rescuers, equipment, diggers, we need relief goods. We need help from the national government, please send in inflatable boats," he said.
Local authorities sent rubber boats and fire trucks to pick up residents but there were not enough to cope, Khonghun added.
Classes were called off throughout the Philippine capital and surrounding areas due to flooding that reached more than five feet (1.5 meters) in some places, said Myrna Puzon, desk officer of the National Disaster Risk Reduction and Management Council.
"It is reaching the second floor of houses. Some people have taken refuge on their rooftops," Puzon said. In the city Olongapo, neighbouring Subic, local officials put up ropes across flooded streets so people could hold on to them to keep from being swept away by strong currents, eyewitnesses said.
People there carried their shivering children as they waded through the floodwaters amid submerged cars. Typhoon Usagi passed the northern Philippines this weekend and has moved away from the country but it continues to exacerbate monsoon rains.
The most severely affected area was the town of Subic, about 80 kilometers northwest of Manila. Heavy rains there caused rain-soaked soil to cascade down, killing six people, said town mayor Jay Khonghun.