A weeklong downpour culminated in raging flash floods that surged through the streets of Jolo's coastal provincial capital Thursday night, sweeping away stilt houses and damaging hundreds of homes, officials and residents said. The floodwaters and sea surges reached 6 feet (1.8 meters) in some areas, the Red Cross reported.
At least five people were killed, including two children, Jolo Mayor Hussin Amin said.
"In my 13 years in politics, I have never experienced anything like what happened last night," Amin told The Associated Press. "We are calling on all good Samaritans to extend support to the people of Jolo."
U.S. troops stationed at Jolo airport, which remained open, joined Philippine marines and civilian volunteers in rubber boats to rescue some of those trapped.
Hundreds of American troops have been training Filipino soldiers who battle Muslim militants hiding in the jungles of Jolo and on nearby islands.
"The water was too deep in some areas that even our trucks could not reach these areas so we had to deploy rubber boats," said Col. Remigio Valdez, a Philippine marine brigade commander on Jolo.
Jolo town, 610 miles (980 kilometers) south of Manila, "is like a catch basin surrounded by mountains so the water from the rains just surged down the slopes into town," Valdez said.
Amin said the floods have affected about 3,500 people in the town, which has a population of about 150,000. He said he ordered the distribution of rice porridge to those in need because shops were closed and the commercial center flooded.
Electricity was cut off and vessels stayed away from the island's port because of big waves.
Disaster officials said at least nine other people have died in floods elsewhere in the Philippines this week, adding to more than 70 lives lost in heavy rainfall between late December and the end of January.
President Benigno Aquino III on Thursday ordered a logging moratorium in the country, blaming the devastating floods on unmitigated logging and deforestation that experts say contribute to soil erosion and trigger mudslides.
Illegal logging is a recurring problem in the country. The U.S.-based environmental group Conservation International says that the Philippines is one of the world's 10 most threatened forest hotspots.