Rainwater was the only source of clean drinking water for some of Burma's cyclone victims Tuesday as the U.N. said only a tiny portion of international aid was reaching the region.

The country's military regime, which has renamed the country Myanmar, has been accused of hoarding high-quality foreign aid for itself while people make do with rotten food.

"There is obviously still a lot of frustration that this aid effort hasn't picked up pace" 10 days after the cyclone hit, said Richard Horsey, the spokesman for the U.N. humanitarian operation in Bangkok, the capital of neighboring Thailand.

Cyclone Nargis devastated Burma's Irrawaddy delta on May 2-3, leaving 34,273 dead, with 27,838 missing, according to the government. The U.N. has suggested the death toll is likely to be more than 100,000.

With their homes washed away and large tracts of land under water, some 2 million survivors —mostly poor rice farmers — are living in abject misery, facing disease and starvation.

The U.N. said the World Food Program is getting in 20 percent of the food needed because of bottlenecks, logistics problems and government-imposed restrictions.

"That is a characterization of the program as a whole. We are not reaching enough people quickly enough," Horsey told The Associated Press.

The survivors are packed into Buddhist monasteries or camping in the open, drinking dirty water contaminated by dead bodies and animal carcasses. Food and medicines are scarce.

The military — which has ruled the country with an iron fist since 1962 — has taken control of most aid sent by other countries including the United States.

The regime told a U.S. military commander who delivered the first American shipment Monday that storm victims' basic needs are being fulfilled — and that "skillful humanitarian workers are not necessary."

But the junta's words and actions have only served to bolster complaints that the military is appropriating the aid for itself.

A longtime foreign resident of Burma's largest city, Rangoon, told the AP in Bangkok by telephone that angry government officials have complained to him about the military misappropriating aid.

He said the officials told him that quantities of the high-energy biscuits rushed into Burma on the WFP's first flights were sent to a military warehouse.

They were exchanged by what the officials said were "tasteless and low-quality" biscuits produced by the Industry Ministry to be handed out to cyclone victims, the foreign resident said.

He spoke on condition of anonymity because identifying himself could jeopardize his safety.

He said it was not known what was happening to the high quality food — whether it was being sold on the black market or consumed by the military.

However, the WFP said it had not heard of its supplies disappearing.

"We've had no reports whatsoever about any incidents of this kind," Marcus Prior, a WFP spokesman, said in Bangkok.

Still, many survivors said they were either not getting any aid or were being handed rotten, moldy rice.

CARE Australia's country director in Burma, Brian Agland, said members of his local staff brought back some of the rotting rice that's being distributed in the delta.

"I have a small sample in my pocket, and it's some of the poorest quality rice we've seen," he said. "It's affected by salt water and it's very old."

It's unclear whether the rice, which is dark gray in color and consists of very small grains, is coming from the government or from mills in the area or warehouses hit by the cyclone.

"Certainly, we are concerned that (poor quality rice) is being distributed," Agland said by telephone from Rangoon. "The level of nutrition is very low."

The foreign resident also said several businessmen have been told to give the government cash donations of no less than $1,800 each to aid cyclone victims.

Companies involved have included jade mining concerns in Hpakant, restaurants and construction companies in Rangoon, he said.

A Myanmar government spokesman refused to comment. The allegations were impossible to confirm independently because of the massive restrictions imposed by the junta on journalists.

Asked whether the United Nations is concerned that food and aid from the U.N. and others that is going into Myanmar is being diverted to non-cyclone victims, U.N. spokeswoman Michele Montas said: "The secretary-general expressed that yesterday ... and that concern exists."

"We don't have any independent report of specific portion of the aid going to other sectors besides the victims," Montas said at U.N. headquarters in New York, acknowledging however there is concern.

The government has also barred nearly all foreigners experienced in managing such catastrophes from going to the delta west of Rangoon, and is expelling those who have managed to go in.

Jean-Sebastien Matte, an emergency coordinator with Doctors Without Borders, said his foreign staff have repeatedly been forced to return to Rangoon from the delta.

Armed police checkpoints were set up outside Rangoon on the roads to the delta, and all foreigners were being sent back by policemen who took down their names and passport numbers.

"No foreigners allowed," a policeman said Tuesday after waving a car back.

After its first aid delivery Monday, the U.S. sent in one more cargo plane Tuesday with 19,900 pounds of blankets, water and mosquito netting. A third flight was to take in a 24,750-pound load.

U.S. Marine Lt. Col. Douglas Powell said that the situation remained fluid, but that flights were expected to continue after Tuesday — which appears to broaden the original agreement for three flights on Monday and Tuesday.

More downpours were expected throughout the week, further hindering aid deliveries.

The Associated Press contributed to this report.