Tropical storm Washi hit the coastal cities of Cagayan de Oro and Iligan, the Philippines over the weekend, leaving over 650 dead and over 900 missing.
Flash floods ravaged a large area of mountainous region on Mindanao island on Friday night, when most victims were asleep in their homes.
Unaccustomed to major storms, the Office of Civil Defence struggled to deal with the number of casualties, with damaged roads hampering relief efforts. "It's overwhelming. We didn't expect these many dead," said Disaster Relief Chief Benito Ramos.
It is estimated that apart from the dead and missing, about 45 000 villagers have been displaced.
Report: Philippines flood toll passes 650 as search continues (BBC News, 18 December 2011)
Health officials said unclaimed bodies were being buried after being marked for possible identification on Monday, as officials said corpses were piling up and mortuaries had run out of coffins.
Mr Ramos told reporters that officials had warned residents of the approaching storm four days in advance, but many people did not evacuate their homes.
But officials complained the area did not receive enough advance warning before disaster struck. "This is the first time this has happened in our city," Vicente Emano, mayor of Cagayan de Oro, said in a radio interview.
In the wake of recent flooding, many are asking why the Philippines, which is hit by an average of 20 typhoons a year, was still caught by surprise.
As waters recede, it is likely that the Aquino government will face questions over the quality of its country's disaster planning and emergency response measures. The floods come a month after Thailand was inundated with mass flooding, during which government handling of the disaster was criticised.
U.S. Secretary of State Hillary Clinton said the United States, a major ally of the Philippines, was ready to assist Philippine authorities. China has also offered disaster relief.
Although the Philippines is struck by several typhoons and tropical storms every year, the south of the country usually escapes the worst damage, with the central and northern parts of the country typically the most affected.
Report: Philippines Storm Death Toll Exceeds 650 (TIME, 18 December 2011)
Report: Swept Away: Flash Floods Ravage Unprepared Philippines (TIME, 17 December 2011)
Report: Philippines searches for missing after typhoon kills 500 (Reuters, 17 December 2011)