May 5 (Bloomberg) -- Almost 4,000 people are dead and 3,000 missing after a tropical cyclone slammed into Myanmar two days ago in the region's deadliest storm-related natural disaster since a tsunami struck Southeast Asia in 2004.

Myanmar's foreign affairs ministry put the possible death toll at more than 10,000, according to Stephanie Bunker, spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs. The government today increased the official toll almost 10-fold to 3,939. About 100,000 people are homeless.

Power was out today in the largest city, Yangon, and drinking water was contaminated in the city of 5 million, the UN news agency IRIN reported, citing officials from the world body.

``The UN will do whatever it can to provide urgent humanitarian assistance,'' Secretary-General Ban Ki-moon told reporters in New York. ``Because of the lack of communications, we are not quite sure what will be the total extent of damages and casualties. I am very much alarmed by incoming views that casualties have risen to more than 10,000, according to Myanmar's foreign ministry.''

Cyclone Nargis packed winds of 120 miles (190 kilometers) per hour when it struck the coast May 3, sending the sea surging as much 12 feet (3.5 meters).

``At least eight townships are completely or mostly destroyed,'' said Pamela Sitko, a worker with the U.S.-based Christian relief group World Vision, who has spoken with colleagues in Myanmar, formerly Burma.

State of Emergency

The government declared a state of emergency in five low- lying provinces, mostly in the Irrawaddy delta, where villages were flattened by winds and rain, the UN said. Myanmar has a population of 47.8 million.

``The water supply is unfit to drink in the aftermath of the destruction, raising fears of water-borne diseases'' in Yangon, IRIN reported.

A United Nations disaster-assessment team is scheduled to arrive tonight in Bangkok, spokesman Farhan Haq said. The UN is prepared to provide a grant from the $500 million Central Emergency Response Fund, created to rush aid to nations in need, he said.

The UN Children's Fund and its Development Program, which have offices in Myanmar, stockpiled food, water and medicine before the storm. They will distribute water-purification tablets, plastic sheeting, food and cooking sets in Yangon and the delta region.

Communications Down

Flooding, blocked roads and disrupted communications are hampering efforts to assess the extent of the damage, according to the world body.

The price of food surged after the cyclone struck, according to the Irrawaddy newspaper, which is published by Myanmar dissidents in neighboring Thailand. An egg now costs between 200 and 250 kyat (20 cents) in Yangon versus 50-70 kyat before the storm, while one viss (1.6 kilograms) of pork is between 8,000 and 8,500 kyat, compared with 4,500 to 5,000.

Myanmar is regularly hit by cyclones that form in the Bay of Bengal between April and November. More than 220,000 people were estimated to have been killed in the 2004 tsunami in the Indian Ocean that struck Indonesia and other Asian nations.

Nargis struck as the nation, which has been ruled by the military since 1962, prepares to hold a referendum on May 10 for a new constitution before elections scheduled for 2010.

Vote Still On

The junta vowed to press ahead with the referendum after the storm, AFP reported, citing a state-run newspaper. The U.S. State Department said April 11 said the referendum is an attempt by the military to retain power. New York-based Human Rights Watch said the vote is being held in a climate of censorship and repression, calling the referendum ``a sham.''

Exiled Myanmar dissident groups called for international assistance to cope with the disaster.

``The military regime is ill-prepared to deal with the aftermath of the cyclone,'' Naing Aung of the Thailand-based Forum for Democracy in Burma said in a statement on the group's Web site. As of yesterday, there were reports the junta still hadn't deployed workers to help clean up, it said, and residents were left to clear debris from the streets of Yangon.

To contact the reporters on this story: Demian McLean in Washington at dmclean8@bloomberg.net; William Varner at the United Nations at wvarner@bloomberg.net.

Last Updated: May 5, 2008 13:48 EDT