Bangkok/Yangon - United Nations emergency relief to the hundreds of thousands of people left homeless and destitute in Myanmar's Irrawaddy Delta by Cyclone Nargis started in earnest Wednesday as the first aid packages were sent to the devastated region.

Chris Kaye, the World Food Programme director in Myanmar, said the first truckloads of food were being dispatched Wednesday to Labutta, a coastal town that lost more than 1,000 people in the cyclone and its accompanying tidal waves.

Myanmar authorities on Tuesday night raised the death toll from the disaster to about 22,500 with more than 41,000 people still listed as missing.

Yangon, Myanmar's largest city and home to millions of people, was among the places worst hit by the cyclone, which struck the country's central coastal region packing 200-kilometre-per-hour winds last Friday.

"Food assistance has now begun to reach persons who are without shelter or food resources in and around Yangon," Kaye said.

She said her agency was awaiting further information from assessment teams in the field before distributing more food "to those who need it the most."

Myanmar's military regime has appealed for international aid, but there have been complaints that the xenophobic generals have not waived visa requirements for foreign aid workers.

On Tuesday Thailand flew the first shipment of medical and food aid to Yangon, where it was received and flown by four military helicopters to areas in the Irrawaddy Delta, state media reported.

It is likely that the military would continue to place controls on the emergency deliveries, especially from sources other than UN agencies, sources said.

"So far, the government has provided some valuable cooperation," Kaye said, adding, "In order to meet the needs of the persons most badly affected by the disaster, much more cooperation will be required in the short term."

The World Food Programme currently has more than 800 metric tons of food stocks available in its warehouses in Yangon.

A joint team from that UN agency as well as another, the Food and Agriculture Organization, is to be dispatched soon to the Irrawaddy Delta, Myanmar's traditional rice bowl, which accounts for an estimated 70 per cent of the country's rice supply.

The cyclone hit when farmers had already planted paddy for the rice crop. It has caused unknown damage to the country's main food staple.

UN experts were predicting more rice price hikes on the world market as the world body is forced to buy emergency supplies in the coming months to stave off widespread shortages in Myanmar in the aftermath of the storm.

Meanwhile, UNICEF announced that 130 of its technical and operations staff were sent Wednesday to cyclone-hit areas to identify the greatest threats to children and women and to deliver supplies.

"Time is of the essence," Ann Veneman, UNICEF executive director, said in New York. "UNICEF had prepositioned emergency supplies, which staff in country are now distributing as quickly as possible, and more staff and supplies are on the way."

The disaster poses particular risks to children.

"In situations such as these, children are highly vulnerable to disease and hunger, and they need immediate help to survive," Veneman said. (dpa)