KACHABADI, Pakistan — It's called Mud Town, or the Place Where the Poor People Live.

Stand back, squint hard and this sprawling refugee camp outside Islamabad could be something out of the 15th century, or the fifth. It's a thousand-acre maze of low-slung, mud-walled hovels, a village of flies and dust and dung and straw, a village of the damned, a place without water, electricity or hope.

"We are temporary people," said one resident who did not give his name. He soldiered for the hard-line Taliban regime for seven years, then packed up and fled last year when he finally had had enough of the fighting. "We live like our animals. I'm a sad man here."

The threat of U.S. strikes against the Taliban has begun yet another refugee crisis, one of Old Testament proportions. The international disaster managers — the diplomats, U.N. staffers and relief workers who try to prepare for emergencies — are expecting more than 1.5 million Afghans to flee if assaults begin.

U.N. refugee workers in Quetta said yesterday "hundreds of thousands" of Afghans already have fled the cities of Kabul, Kandahar and Jalalabad, all Taliban strongholds considered the most likely targets of any U.S. attacks.

The U.N. refugee agency (UNHCR) said it was preparing for an exodus of Afghans to neighboring countries — nearly 1 million could arrive in Pakistan and half a million in Iran.

UNHCR spokesman Yusuf Hassan told Reuters plans were being drawn up in Tajikistan, Uzbekistan and Turkmenistan to accommodate 150,000 more refugees. About 3.7 million Afghans already have fled their homeland and form the world's largest refugee population.

The Pakistan-Afghan border, stretching 1,400 miles, remains an obstacle for Afghans trying to flee because Islamabad is locking its gates, except to those with valid visas.

An estimated 10,000 to 20,000 people have arrived at the border near the southwestern town of Chaman, but Pakistani authorities are blocking their entry while U.N. officials look for places to set up 20,000 tents and move in 17 tons of food stockpiled nearby.

"A humanitarian crisis of stunning proportions is unfolding in Afghanistan," said a U.N. statement issued in Geneva and Islamabad, the Pakistani capital.

To escape the fighting, food shortages and coming winter, these refugees will become the next generation of temporary people living in an urban hell like Mud Town.

Of the current camps, Jalozai, a tent city east of Peshawar in Pakistan's Northwest Frontier Province, is the most notorious for its living — or dying — conditions for the 55,000 or more Afghans there. Aid workers say children at the camp are dying daily, almost routinely, from dehydration, dysentery and starvation.

"Pakistan has a long history of taking in refugees and a remarkable record of hospitality," said a U.S. diplomat based in Islamabad, who spoke on condition of anonymity. "But that welcome isn't there anymore. The Pakistanis, quite frankly, are freaking out."

In panic, the government has appealed to the United Nations and international aid agencies. The details of Islamabad's rescue plan will be announced this week.

"We've tried to give Pakistan some assurances that when the time comes, we'll be there to help them shoulder the burden," said the U.S. official, who put annual U.S. refugee assistance at $170 million.

Abdul Majid, a 13-year-old Afghan, hasn't seen the first rupee of any aid. He came to Mud Town last year from Jalalabad with his mother and five siblings shortly after his father died from drinking tea made with polluted water.

Majid works every morning in a nearby market, where he gets enough to eat — grapes from Kabul, bananas from Karachi, oranges from the Punjab region, apples from Quetta. He spends his afternoons as a tailor's apprentice.

There's no school or books, and even if he wanted to study at night, there are no electric lights.

Other members of his family have been in Pakistan for three years. His mother is eager to go back to Afghanistan.

"We'll go when there's no more fighting," Majid said. "When there's no more Taliban."

The United Nations has been supporting 5 million Afghans inside the country after decades of war and three years of severe drought, said Ross Mountain, the U.N. head of humanitarian coordination in Geneva. Under the worst conditions, the number of people desperately needing U.N. aid could increase by 50 percent to 7½ million, he said.

Many of those already at risk are women and children "with a fragile grip on survival," said a U.N. statement. "The onset of winter will loosen that grip even further."

The foreign staff of the United Nations and virtually all nongovernmental organizations have been evacuated. And the Taliban have restricted or stopped the activities of local staffers who remained.

Over the weekend the Taliban shut down and occupied all U.N. offices in Kandahar, the militia's spiritual capital. They also prohibited most U.N. workers from using communication equipment, effectively cutting them off from the outside world, said U.N. spokeswoman Stephanie Bunker.