CAGAYAN DE ORO, Philippines - Rescuers searched for more than 800 people missing in the southern Philippines on Sunday after flash floods and landslides swept houses into rivers and out to sea, killing more than 650 people in areas ill-prepared to cope with storms.Cagayan de Oro and nearby Iligan cities on Mindanao island were worst hit when Typhoon Washi slammed ashore while people slept late on Friday and early Saturday, sending torrents of water and mud through villages and stripping mountainsides bare.The Philippine National Red Cross (PNRC) said 652 people were killed in eight provinces in the southern Mindanao region, with more than 800 missing."Our office was swamped with hundreds of requests to help find their missing parents, children and relatives," Gwendolyn Pang, secretary-general of the PNRC, told reporters. "We're helping coordinate the search with local government, army, police and even other aid agencies."Floods washed away entire houses with families inside in dozens of coastal villages in Cagayan de Oro and Iligan."This is the first time this has happened in our city," Vicente Emano, mayor of Cagayan de Oro, said in a radio interview. He said officials in the area did not receive adequate warning before the typhoon struck.The state disaster agency said adequate warnings had been given to officials and residents three days before the typhoon made landfall on Friday.BODIES PILED UP; SOLDIERS BUILD COFFINSDisaster and health officials were struggling to deal with the scores of bodies that have been recovered. Some were stacked one on top of each other in under-staffed mortuaries that were unable to cope with the numbers of dead."I saw for myself bloated bodies of women and children, not less than 100," Vice President Jejomar Binay told Philippines radio as he toured the worst hit areas in Cagayan de Oro.Binay distributed food packs and ordered the relocation of families living near waterways and other hazards.Brigadier General Roland Amarille, head of an army task force in Iligan, said soldiers had been mobilized to recover bodies and build coffins."We need body bags and lime to deal with too many cadavers," Amarille said, fearing an outbreak of disease."Local mortuaries are no longer accepting cadavers and they are even asking people to bury the dead at once because there are too many bodies even in hallways," he said.Most of the fatalities were from a slum area on an island sandwiched by two rivers in Iligan. "About 70 percent of the houses on the island were washed into the sea," Amarille said.Mindanao island, the southernmost in the Philippines, is a mineral-rich region that also produces rice and corn but is not normally in the path of an average 20 typhoons that hit the Southeast Asian country each year."This poses challenges to us ... We need to educate people with this kind of change in climate," Pang said. "The volume of rainfall for one month fell in just one day."RESCUED BY CARGO SHIPTyphoons normally strike the central Visayas region and the south and east of Luzon, the main island in the north.Carmelita Pulosan, 42, said she and eight family members and neighbours survived by sitting on top of the tin roof of their house as it drifted miles into the open sea after floodwater swept through their village.They were rescued by a cargo ship."There was a deafening sound followed by a rush of water. We found ourselves in the river and the current took us out to the sea," Pulosan, from Cagayan de Oro, told Reuters."The current was very strong. God is really good to us. He saved my family," she said. Only one 3-storey building was left standing in their village, Pulosan said.Red Cross official Pang said officials and residents did not expect such a huge volume of water cascading down mountains into river systems because the area was not in the typhoon belt.She said Cagayan de Oro last experienced floods in 2009 but there was only minimal damage and no deaths.Many people found their homes destroyed after returning to shattered villages, Pang said.U.S. Secretary of State Hillary Clinton said the United States, a major ally of the Philippines, was ready to help. The Chinese embassy would donate $10,000 to help in the relief efforts, an embassy official said.Washi, downgraded to a tropical storm with gusts of up to 80 km per hour (50 miles per hour), was hovering about 60 km (40 miles) west of the southwestern city of Puerto Princesa and was expected to move out of Philippine waters late on Sunday.