In a cold and driving rain, a dozen young men stood by the side of the road Tuesday afternoon, flagging down any vehicle that passed. A truck pulled over and they ran to the driver's window, pleading in vain for tents and blankets to shelter their families.

"My house has collapsed," said Wagar Ahmed, 21, waiting along the road for the second day after walking an hour and a half from his remote mountain village. "We have all grouped together to ask for help."

The moment illustrated the growing desperation of survivors of the massive earthquake on Saturday that killed an estimated 20,000 to 40,000 people across Pakistan-controlled Kashmir and adjacent areas. One million people were thought to be left homeless.

With worsening weather and rising fears of hunger and disease, people in many stricken areas had yet to see evidence of a government and international relief effort that was attempting to rush in food, shelter and rescue equipment. Countless mud-brick villages -- many of them virtually destroyed -- cling to the sides of Kashmir's forested mountains and are difficult to access in the best of times. The quake was centered in Pakistan, but struck a wide swath of territory in South Asia, affecting parts of India and adjacent areas of Afghanistan.

The devastation was evident during a four-hour drive through part of Kashmir. Families huddled in ruins or stood in the soaking rain as lightning crackled over nearby mountaintops. No international aid vehicles, and only a handful of army trucks, were visible along the route of roughly 50 miles, made nearly impassable in places by rockslides.

The scene was similar in Rawalakot, a once-pleasant town of about 60,000 people that is one of the largest in Pakistani-controlled Kashmir. "We are badly surprised that we didn't see any Red Cross, any donor agency," said Abid Hussain, a businessman and former chairman of the local development authority. "We didn't receive a single injection" of medicine.

Although there is an army garrison nearby, troops were busy tending to their own dead and injured, and only a few soldiers were visible in the main part of town on Tuesday. The earthquake killed an estimated 600 people in Rawalakot and destroyed a college as well as both the military and civilian hospitals in town. In the absence of other assistance, Hussain directed rescue operations on his own, renting two backhoes from a contractor to clear rubble and turning over his wedding hall for use as a medical clinic.

The wedding hall was formerly attached to his four-story hotel, now in ruins with several bodies believed to be inside. Hundreds of homes in the town were destroyed and survivors were camping outside. "We are badly in need of tents," said Hussain, a sturdy-looking man with a commanding presence. "Ninety percent of our population is beneath the blue sky."

The weather worsened over Pakistani-controlled Kashmir and adjacent damaged areas to the west, grounding helicopters and slowing efforts to deliver relief supplies and evacuate the injured. Interior Minister Aftab Khan Sherpao, meanwhile, raised the estimated death toll in Pakistan to at least 33,000; another 2,000 are reported to have died in the part of Kashmir controlled by India, just across the cease-fire line that divides Pakistani and Indian forces in the disputed Himalayan region.

In response to the 7.6-magnitude earthquake, the strongest to hit Pakistan in a century, the United Nations and numerous foreign governments have pledged assistance, and experts from international relief groups were busy assessing where and how to distribute the aid.

U.N. agencies estimated that a million people were in need of food and housing; officials at the World Food Program said the first shipment of food -- enough to feed 240,000 for five days -- was en route from Italy and could arrive by Wednesday.

"This food is needed urgently," Amjad Jamal, a World Food Program spokesman, told the Reuters news agency. "People are trying to recover from a major disaster; they are in shock and their bodily resistance will go down if they do not have enough food."

But the task of providing earthquake victims with food -- as well as other basic needs such as shelter and medical care -- has been greatly complicated by the vast size of the affected area and the inaccessibility of many stricken villages, some of which have been cut off by landslides.

With most victims still awaiting help, there were growing fears of the threat posed by disease and exposure, with nighttime temperatures plunging toward freezing in the mountainous areas where most of the damage occurred.

Khawaja Shabir, director general of health in Pakistani-controlled Kashmir, told Reuters that health services in Muzaffarabad, the capital of the region, have "totally collapsed" and that "malaria, gastroenteritis and waterborne diseases have already spread in worst-hit areas of the city." At least 10,000 people are thought to have died in Muzaffarabad, where most buildings were destroyed or badly damaged.

Ronald van Dijk, UNICEF's senior representative in Pakistan, described the situation as "extremely urgent," Reuters reported. "It's October, it's very cold at night and there are entire villages flattened, so people have to sleep in the open. In addition, there are many injured people, including children, and fresh water supplies have been damaged."

There were a few moments of optimism on Tuesday. In Balakot, a heavily damaged town in Pakistan's North-West Frontier province, adjacent to Kashmir, rescuers shouting "He's alive!" pulled a teenage boy from a wrecked building, 78 hours after the quake, the Associated Press reported. In Islamabad, the capital, a 55-year-old woman and her 75-year-old mother were found in good condition in the wreckage of 10-story apartment building 80 hours after it collapsed.

But there was no evidence of rescue or relief operations in other parts of the stricken zone.

The young men waiting by the side of the road to Rawalakot, for example, came from the village of Danna, a collection of about 1,000 mud-and-stone houses scattered across five or six miles of forest and terraced farm fields. Not visible from the asphalt road, the houses are strung out along a stony track that on Tuesday was barely navigable by four-wheel-drive vehicle because of small landslides.

The earthquake killed about 150 people in Danna, including 20 children who died when the middle school collapsed, according to Wagar Ahmed, the young man whose house was one of many in the village that were destroyed. A delivery-truck driver, Ahmed lived in the house with his parents and six siblings, including a 6-year-old brother and 7-year-old sister.

With the home now resembling a refuse pile, the men in the family have been sleeping outside while the others have taken refuge in the partially collapsed house of a relative next door. "It was very cold, and it started raining this morning at 10," said Ahmed, a small man wrapped in a thin woolen scarf who appeared exhausted.

Back down the mountain and closer to Rawalakot, Mohammed Hasrat, 20, walked in the rain along the side of the road, shivering in a thin shirt and slacks. He carried a blanket and a change of clothes in a plastic bag and said he was returning home from the town of Bagh, where several relatives had died.

Gratefully accepting a lift, he said that the earthquake had destroyed most of the homes in his village and that most people there were spending the nights outside, including his nephews, ages 3 and 4, whose parents had covered them with cattle fodder to keep them warm.

"Nobody has brought us tents," said Hasrat, whose village is accessible only by foot. "Everyone sleeps in the fields or the forest."

Even in a relatively prominent and prosperous community such as Rawalakot, many people were living in the open. Among them was an elderly couple, Mohammed and Jehan Akhbar, who until Saturday occupied a metal-roofed stone house a short walk from the main bazaar. Now they live under a plastic sheet on a muddy patch of earth littered with straw and wet cardboard.

"We need a solid tent," said Jehan Akhbar, as her husband, an amputee, tried to stay warm under a pile of blankets. "We need something to eat."

Homeless children find shelter from the rain under a tarp in Balakot, Pakistan, one of the towns hit hardest by Saturday's earthquake. Rain also hampered rescue efforts. A teenager is rescued in good condition from the rubble of a restaurant in Balakot, Pakistan, where he had been trapped since Saturday's earthquake.