MUZAFFARABAD, Pakistan - Heavy rain and hail forced the cancellation of some relief flights to earthquake-stricken regions today and survivors scuffled over the badly needed food - the first international aid to make it overland to this devastated city. Officials estimated that the death toll would surpass 35,000.

In the latest of a series of remarkable rescues, emergency workers in the northern town of Balakot pulled a teenage boy from the rubble today, 78 hours after Saturday's quake.

"He's alive!" rescuers shouted as people gave food and water to the boy and kissed him on the head.

Two survivors, a 55-year-old woman and her 75-year-old mother, also were pulled from the rubble of a quake-hit apartment building in Islamabad, 80 hours after they were buried. They did not appear to have suffered serious injuries.

A French search team on Monday rescued at least five children buried in a collapsed school in the northern town of Balakot, said Eric Supara, an official at the French Embassy in Islamabad.

Earlier in the day, U.S. military helicopters, diverted from neighboring Afghanistan, helped ferry wounded from the wrecked city of Muzaffarabad, while international rescue teams joined the search for finding survivors. Teams of Britons, Germans and Turks used high-tech cameras to scan under piles of concrete, steel and wood.

Thousands of civilian volunteers, some carrying picks and shovels on their shoulders, walked north toward quake-hit towns.

Bad weather compounded the misery in the region, with heavy rain and hail forcing some helicopters loaded with food and medicine to cancel or delay their flights.

The official death toll remained at around 20,000 people, but a senior army official close to the rescue operations said government officials were estimating that between 35,000 and 40,000 died. The official asked not to be identified because he wasn't authorized to disclose the estimate to journalists.

About 10 trucks brought by Pakistani charities and volunteers rumbled into Muzaffarabad, where efforts by relief workers to distribute aid turned chaotic as residents scrambled for handouts of cooking oil, sugar, rice, blankets and tents.

It was the first major influx of aid since the monster 7.6-magnitude quake struck Saturday morning, destroying most homes and all government buildings in this city, and leaving its 600,000 people without power or water. Most have spent three cold nights without shelter.

Two or three police looked on helplessly as more than 200 people raided a stock of food arranged by relief workers at a soccer field near Muzaffarabad's center - one of six designated aid distribution points. One man made off with a big sack of sugar, another left on a motorized rickshaw with a big crate of drinking water.

"Relief activity has started on a massive level," said deputy city commissioner Masood-ur Rehman. He said two army brigades would start clearing roads and debris in the city.

With winter just six weeks away, the United Nations said 2.5 million people in the worst-hit areas near the mountainous Pakistan-India border need shelter. The U.N. World Food Program began a major airlift of emergency supplies.Pakistan army spokesman Maj. Gen. Shaukat Sultan said a total of 30 helicopters, including eight U.S. military choppers diverted from the war in Afghanistan, would be supplying food, water, medicine and other items to quake victims. Two more German and four Afghan helicopters were sent, he said.Even longtime foe India planned to send a planeload of food, tents and medicine after Pakistan set aside its often-bitter rivalry with its nuclear neighbor and said that it would accept New Delhi's aid. Islamabad, however, declined an offer of Indian helicopters.Indian Prime Minister Manmohan Singh described the earthquake in Kashmir as a national calamity, saying the government will spare no expense to help the survivors.Singh said India's death toll had reached 1,300, with another 4,500 injured and 32,000 houses were damaged."Whatever is necessary, whatever is needed to rehabilitate, whatever is needed for relief, the central government stands committed to help," he said. Singh earlier announced another $111 million in assistance in addition to the $26 million already promised by his government for relief in the Himalayan territory.President Gen. Pervez Musharraf said his government was doing its best to respond to the crisis."We are doing whatever is humanly possible," Musharraf said. "There should not be any blame game. We are trying to reach all those areas where people need our help."In Muzaffarabad, a doctor, Iqbal Khan, said survivors were at risk for diarrhea and pneumonia if drinking water and other supplies did not arrive quickly.In the Pakistani capital of Islamabad, rescuers continued digging through the ruins of a 10-story apartment building after pulling a woman and child to safety. Asim Shafik, who was assisting in rescue efforts, said voices were heard in the rubble, where at least two dozen people died.