Cyclone Sidr affected more than 8.5 million people roughly 1.5 million more than initially assessed the U.N. Office for the Coordination of Humanitarian Affairs, or OCHA, said on its Web site.
"As more information becomes available, an even grimmer reality is being revealed," said an OCHA report, initially issued in New York. Because some cyclone-affected areas became accessible only recently, more reports on the extent of the damage were still coming in, it said.
The category 4 storm, with winds of 240 kph (150 mph) and torrential rains, devastated 31 districts along the country's coast on Nov. 15, said the OCHA report, which was compiled with help from local and international agencies.
"Material damages caused by Sidr are much more significant than previous estimates indicated," it said.
Nearly 564,000 houses were completely destroyed 200,000 more than reported earlier, while another 885,280 were partially damaged. Some 1,355 schools were also destroyed, while another 7,847 were damaged.
In addition, crops were damaged on more than 2 million acres (809,389 hectares) of land, while over 1.25 million livestock were killed. The cattle and poultry death toll was twice than originally estimated.
The U.N. assessments identified food, shelter and cash as the highest priority needs for an estimated 2.6 million people in nine worst-hit districts.
Drinking water, sanitation, electricity, livelihood and rehabilitation assistance were also urgently needed, it said.
The U.N. put the death toll at 3,268, with at least 872 people still missing.
However, the Bangladesh government Disaster Management Information Center put the number of dead at 3,292 on Tuesday, and said the number injured was 40,000.
Government and voluntary medical teams are still working in the affected areas, where maladies such as typhoid, fever, diarrhea, pneumonia and skin rashes were detected.
The U.N. Central Emergency Response Fund says it has so far disbursed about US$14.7 million (Ђ10 million) for relief.
"Nevertheless, as assessments are ongoing, additional funds might be required in order to provide comprehensive humanitarian assistance ... as new needs continue to be identified," it said.
The government, meanwhile, estimated that nearly US$1 billion (Ђ682.25 million) would be required for rebuilding infrastructure and restoring livelihoods in the cyclone-hit areas, the country's interim leader Fakhruddin Ahmed said Monday after meeting with foreign envoys.
The government estimates include US$250 million (Ђ169.6 million) for rebuilding coastal embankments, US$100 million (Ђ67.84 million) for rebuilding schools and US$300 million (Ђ203.51 million) for repairing roads and bridges.