ILIGAN, Philippines - Mass burial sites were set up on Monday for decomposing bodies of flood victims after tropical storm Sendong (international name: Washi) left more than 600 people dead on the southern island of Mindanao.
Officials in the port cities of Cagayan de Oro and Iligan where sleeping families were swept to sea from coastal slums, said unclaimed cadavers piling up in mortuaries were posing health risks and had to be interred.
Burials were expected to take place starting Tuesday, local officials said.
The Philippine Red Cross set the death toll from Saturday's flash floods spawned by tropical storm Sendong at 652 while the national disaster council put the figure at 632. Estimates of the missing persons varied widely.
Most of the dead were from the two cities, which were built around river systems that overflowed when a month's volume of rain fell in a 24-hour period.
The disaster area, located about 800 kilometres (500 miles) from the capital Manila, is normally bypassed by typhoons that ravage other parts of the far-flung Philippine archipelago every year.
Teresita Badiang, an engineer at the Iligan mayor's office, said the city had begun constructing two concrete communal tombs where cadavers would be placed side by side "so that their burial will be dignified."
The disaster council said at least 227 people died in Iligan.
Television footage from an Iligan mortuary showed a corridor lined with bodies wrapped in white plastic bags bound with tan-coloured packaging tape.
In Cagayan de Oro, where the disaster council placed the death toll at 336, Mayor Vicente Emano said a mass burial would be held within the week but aides said the exact location had not been finalised.
Dr Jaime Bernadas, the department of health's director for the region, said cadavers were still being processed prior to "temporary burial" in the city.
Health officials were taking DNA samples and photographs of victims.
"We are giving time for relatives to claim (the bodies)," he told AFP by telephone.
About 47,000 evacuees are now huddled in evacuation centres in Sendong's wake, mostly in the northern coast of Mindanao, a vast poverty-stricken island troubled for decades by a Muslim separatist insurgency.
Dr Eric Tayag, head of the national epidemiology centre in Manila, said the government was taking steps to prevent outbreaks of cholera, dysentery, dengue and respiratory problems particularly in congested evacuation centres.
"Around 10 days after this flooding there might be an epidemic of water-borne diseases," Tayag warned on television.
Philippine Red Cross chief Gwendolyn Pang said strict guidelines had to be followed in mass burials, including photographing corpses, listing identifying marks and laying them a meter (yard) apart for possible exhumation.
"I'm sure their families will look for them," she told AFP.
President Benigno Aquino is set to visit the stricken zone on Tuesday after ordering a review of the country's disaster defences.
Benito Ramos, the government's disaster agency chief, said most of the victims were "informal settlers" -- a term typically used for slum squatters who are often unregistered by authorities.
Authorities likened tropical storm Sendong to Ondoy (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, killing more than 460 people.