A young medical student, Binod Rai, was breathing heavily after a 45-minute hike into the mountains on a mission to help earthquake victims who had not yet been reached.

Rounding a bend, he confronted a scene surpassing his worst expectations. Every hut in this hamlet atop a peak in Pakistani-controlled Kashmir had collapsed into a pile of rubble. Entire families -- parents and children -- were lying under makeshift shelters of tin and straw in the debris, moaning in pain from open wounds.

Rai, 24, began dabbing iodine on lesions and applying fresh bandages where he could.

"She has gangrene. This is a very, very serious injury," he said to a man whose mother lost most of an earlobe when she was hit by a falling rock. "You need to take her down the mountain for treatment as soon as possible."

The man, a 50-year-old laborer who goes by the single name Manna, hung his head. There were simply not enough healthy men left in the village to carry out the injured.

"We are totally hopeless," he mumbled.

It was a common refrain Thursday across northeastern Pakistan, five days after the strongest earthquake in the country in a century.

Between 25,000 and 35,000 people are now believed to have died in the quake. The United Nations estimates that 4 million people have been affected by the disaster, including 2 million who lost homes. Shelter is the most immediate need, and there are growing fears of hunger and disease.

In Islamabad, the capital, Jan Egeland, the top relief official at the United Nations, said Thursday that relief efforts were not keeping pace with the needs of hungry and homeless survivors across the vast earthquake zone, many in isolated mountain villages such as Hariala where the onset of the harsh Kashmiri winter is only weeks away.

"I fear we are losing the race against the clock in the small villages," Egeland told reporters after flying by helicopter to Muzaffarabad, the leveled capital of Pakistani-controlled Kashmir. "I've never seen so much devastation before. . . . Every day the scale of devastation is getting wider."

Whatever aid has reached remote villages has been delivered largely in an ad hoc fashion by volunteers such as Rai. But they have been hampered by a lack of resources and coordination as well as by the growing threat posed by violent looters.

All three problems were in evidence on Rai's trip to Hariala. He was accompanied by a tightknit group of friends from the Frontier Medical College in the nearby city of Abbottabad, who pitched in to help the relief effort since the quake struck on Saturday.

Rai, a soft-spoken native of Nepal, is one of the top students at the college, his friends said, and despite being reserved, he has a wry sense of humor.

The students planned to drive from Abbottabad to Garhi Habibullah, a sprawling town at the bottom of a high, narrow ridge separating the disputed province of Kashmir from the rest of Pakistan. From there they would take vehicles rented by a charity called the United Nations Association of Pakistan up the rugged dirt track ending in the village of Shaheed Galik. There, they hoped to establish a first-aid camp to help stabilize villagers walking down the mountain en route to a field hospital run by army and civilian doctors in Garhi Habibullah.

Transferring to a black Jeep, they crossed a bridge and rumbled off the paved road onto a rocky path. For the next half-hour, it wound higher and higher past cliffs covered in gold-colored grass and soaring fir trees. Spectacular purple and white peaks loomed in the distance.

But the natural beauty was marred by the signs of human misery at every turn: Mud huts were flattened, improvised tents teemed with dazed villagers. There were large fissures in the road where the quake had pulled the ground apart; in the valley below, the students could see the vast field of rubble that was once the scenic city of Muzaffarabad.

At Shaheed Galik, they were pleased to discover that a doctor and two businessmen had already set up a table with free medicine for villagers in need. There was also a man with a long beard belonging to the Islamic group Jamaat ul-Dawa, a reconstituted version of the Islamic group Lashkar-i-Taiba, which the Pakistani government has outlawed for alleged links to terrorism. He had traveled with an ambulance belonging to the group.

However, there was no sign of a government or international presence.

Egeland said he thought the international response thus far was "not bad," adding, "Tens of thousands of tents, hundreds of thousands of tons of emergency food, a million blankets and other relief goods are in the pipeline."

"We have seen a much graver picture and I believe we need to triple the number of helicopters in the operation," Egeland said. "My appeal to the world is to come up with more aid, more relief and more resources."

The United Nations has appealed for $272 million for six months of emergency aid, and so far about 30 countries, including the United States, have pledged assistance of one form or another. U.S. helicopters diverted from military operations in neighboring Afghanistan have already begun shuttling supplies and evacuating injured.

Back at Shaheed Galik, the students were debating where they should establish their first-aid camp.

"We need to make sure it's not near any walls, in case there is another jolt," said Jazed Mahmood, a 23-year-old with wire-rimmed glasses and a mature air. Aftershocks to the Saturday earthquake have been frequent.

Suddenly, a red off-road vehicle loaded with blankets and water screeched into the main square. Several men jumped out, one of them sobbing. They were volunteers from the city of Lahore, they called out, and said they had just been attacked by residents of the village one stop over when they refused to hand over all their supplies.

"Why did they beat us?" Arif Mahood shouted through his peers. "We have come all this way to help."

"No matter, no matter," said Bashir Ahmad, a district judge who lives in the village and has become a de facto leader there. "Please be patient, we are very grateful to you." But the volunteers were not mollified. They said they would provide the supplies only if Ahmad handled the distribution.

Ahmad coaxed the gathering crowd of villagers into an orderly line in front of the Jeep, prodding them with a long stick. But as soon as his back was turned, they swarmed over the vehicle and began tossing out the contents. Precious bottles of water splattered on the ground.

Salahuddine Khan, 23, a burly student who is normally the cut-up of the group, looked on gravely.

"I don't know if it's a good idea to set up the first-aid camp here," he said. "Look at the people. If, God forbid, someone comes for treatment and dies, these people will blame us and beat us to death." But Rai insisted they press on to investigate reports of hundreds of grievously injured residents in villages above that were accessible only by foot.

At every turn, he saw villagers carrying down their wounded: two men bearing a boy on a stretcher with deep cuts on his arm and ankle; an elderly man lugging an even more elderly woman on his back; a husband leading his disoriented wife, who stopped for a moment to show Rai the deep crack in her skull.

Still, at least these villagers were able to leave their hamlet to seek help.

Rai lit a cigarette and took a long drag. "I wanted to become a doctor because I feel like saving the life of another human being is a very royal job," he said, hiking down toward the Jeep. "But out here, with no medicines or possibility of surgery, I feel totally useless."

Correspondent John Lancaster in Islamabad contributed to this report.

A family waits to be airlifted by helicopter from the town of Balakot, where many refugees have gathered to seek medical attention.