MUZAFFARABAD, Pakistan (AP) - Heavy rain and hail grounded helicopters and stopped trucks loaded with relief supplies yesterday, imposing more misery on hungry, shivering earthquake survivors as the United Nations warned of potentially lethal outbreaks of measles, cholera and diarrhea.

Dazed, desperate villagers fought over food packages and looted trucks as the first aid reached this devastated city in the mountains of Kashmir. The Himalayan region was hardest-hit by Saturday's magnitude-7.6 quake.

Officials said the death toll from Pakistan's worst quake had surpassed 35,000, with many bodies still buried beneath piles of concrete, steel and wood. Millions were left homeless after whole communities were flattened in the region touching Pakistan, India and Afghanistan.

Three days after the quake, survivors still were being pulled from the rubble of pancaked schools and houses by British, German, French and Chinese rescue teams. A Red Cross official said people could survive under the rubble up to five or even seven days.

A 75-year-old woman and her 57-year-old daughter were rescued after 80 hours in the ruins of an Islamabad apartment tower, and a teenage boy was freed in the northern town of Balakot.

"He's alive!" rescuers shouted with joy as people gave the boy food and water and kissed him on the head. The air smelled of decomposing corpses.

The U.N. World Food Program began a major airlift of emergency supplies, including high-energy bars to feed 240,000 people.

NATO agreed to coordinate an airlift of aid supplies from Europe. Eight U.S. military helicopters based in neighboring Afghanistan shuttled 16 tons of food, water, medical supplies and blankets to quake-hit zones, the military said.

Chinook and Black Hawk choppers flew 102 relief workers and others into the region and evacuated 126 people, said Lt. Col. Jerry O'Hara, spokesman for the U.S. base at Bagram, Afghanistan.

In Washington, a Pentagon spokesman said 25 to 30 more military helicopters would be in Pakistan within days. The Islamabad government also requested earthmovers, forklifts, bulldozers and trucks, spokesman Larry Di Rita said.

The United Nations appealed for $272 million in donations, saying 2 million people were homeless. The United States pledged $50 million, Japan $20 million, Canada $17 million and Britain $3.5 million. Other nations donated more helicopters, money and supplies, including tents, blankets, medical aid and food kits.

"We as a nation are going through a challenging time," Pakistan Prime Minister Shaukat Aziz said. "We are overwhelmed by the support we are getting both within the country and outside the country and are thankful to those countries, friends and individuals who have made our task easier."

Yesterday's efforts were hampered by torrential rains and hail in the mountains of the Pakistani side of Kashmir, and crates of supplies sat on tarmacs waiting to be delivered. At least one U.S. supply helicopter had to turn around because of a rainstorm in the mountain passes, the military said.

"The recovery efforts have been slowed by bad weather and large parts of the region are still inaccessible because landslides have destroyed the road network," a U.N. statement said.

Bob McKerrow, coordinator of relief efforts for the International Federation of the Red Cross, said in Islamabad that 17 trucks left for affected areas with supplies, including blood.

"Some of the roads are just being reopened and this rain is not going to help at all," McKerrow said. "And the possibility of further landslides blocking roads is a threat every minute of the day."

The Pakistani government's official death toll was about 23,000, but a senior army official involved in the rescue operations said that "according to our assessment, the death toll is between 35,000 to 40,000 people." Tens of thousands were injured.

The official spoke on condition of anonymity because he was not authorized to talk to the media about the toll. The estimate matched that of local officials.

Neighboring India said 1,300 people died in its part of Kashmir, the disputed province at the center of two wars between New Delhi and Islamabad.

India planned to send a planeload of food, tents and medicine to its longtime rival in what was seen as a boost to the peace process between the two nuclear-armed neighbors. Islamabad, however, refused India's offer of helicopters.

One of the places hardest-hit by the quake was Muzaffarabad, the capital of Pakistani-controlled Kashmir, where most homes and all government buildings were destroyed. Bodies were still in the streets.