Nearly 1,000 people have been killed after flash floods and land slides, caused by Typhoon Washi, swept through riverside and coastal villages in the southern Philippines late last week, the national disaster agency has said.
The agency announced on Tuesday 957 were killed and 49 were missing, with most of the casualties coming from the cities of Cagayan de Oro and Iligan. The previous death toll was 650.
Authorities in the two cities - hit hard by water, mud and logs swept down mountains - are struggling to prevent disease from spreading in crowded evacuation centres, and have started digging mass graves to bury decomposing bodies.
President Benigno Aquino will visit the two cities later on Tuesday.
The government said more than 338,000 people were affected by the disaster on Monday, although government officials said the figures for the missing may have been overstated in the post-disaster chaos.
"Today we will dig a mass grave and bury the unclaimed bodies as well as those in an advanced state of decomposition," Lawrence Cruz, mayor of Iligan, said on Monday.
Television footage from an Iligan mortuary showed a corridor lined with bodies awaiting burial, wrapped in white plastic bags bound tightly with tan-coloured packaging tape.
About 47,000 evacuees are currently huddled in evacuation centres in Washi's wake, mostly on the northern coast of Mindanao, a vast poverty-stricken island where Islamic separatists have battled against authorities for decades.
Rescue and relief efforts were being spearheaded by government troops normally assigned to fight rebels elsewhere on the island.
Pope Benedict XVI, the head of the Catholic Church, prayed for the victims of the latest natural disaster to hit the largely Roman Catholic archipelago, which is also prone to earthquakes and volcanic eruptions.
The US offered assistance as Manila appealed for help to feed, clothe and house the thousands sheltering in evacuation centres, including many residents of shanty towns whose makeshift homes were destroyed by the storm.
Ramos, the disaster agency chief, said most of the victims were "informal settlers" - a term used for shanty town residents who are often unregistered by authorities.
One month's worth of normal rain fell in the affected area within a 24-hour period but residents, who were normally spared from typhoons that regularly hit other regions of the Philippines, ignored warnings to move to safe ground.
Authorities likened tropical storm Washi to 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.