MINGORA: Doctors rushed to treat wounded Pakistani civilians and desperate refugees looted UN supplies today, as thousands of troops backed by bomb-dropping warplanes sought to purge Taliban militants from a northwestern valley.

A suspected US missile strike killed nine people, mostly foreigners, in another militant stronghold near the Afghan border, officials said. The identities of the victims were not immediately unclear.

Pakistan's leaders, encouraged by the United States, launched a full-scale offensive in the Swat Valley this week to halt the spread of Taliban control in districts within 100 km of the capital.

But the fighting has caused hundreds of thousands of terrified residents to flee, adding a humanitarian emergency to the nuclear-armed nation's security, economic and political problems.

Witness accounts indicated that scores of civilians have already been killed or injured in the escalating clashes in Swat and the neighbouring Buner and Lower Dir districts.

Medics at the hospital in Swat's main town, Mingora, were working at full stretch to deal with scores of residents caught up in the fighting.

Riaz Khan, a 36-year-old school teacher, his wife and two daughters occupied four of the beds, the shrapnel wounds on their arms and legs covered by bandages.

Khan said his other two daughters were killed three days earlier when a mortar shell hit their home near Mingora.

"We buried our daughters on Thursday when the army relaxed the curfew," he told an Associated Press reporter. "We reached the hospital only with great difficulty." Nisar Khan, one of only three doctors left at the hospital, said there were about 25 war-wounded among the 100 patients.

The unidentified bodies of three women and a man apparently killed in the fighting were also being kept there, even though the hospital had no morgue, he said.

Pakistan's army is fighting to wrest Swat and neighbouring districts from militants who dominate the adjoining tribal belt along the Afghan frontier, where US officials say al-Qaida chief Osama bin Laden is likely holed up.

Taliban militants seized much of the area under a peace deal, even after the government agreed to their main demand to impose Islamic law in the region.

There were scuffles today between police and dwellers of one of the still-crude camps mushrooming around the city of Mardan, just south of the war zone.

Television image showed dozens of men making off with blankets and tins of cooking oil. A policeman thumped one looter with the butt of his rifle while a man wearing a T-shirt bearing a UN logo urged others to return their booty.

"When people are desperate, it's hardly surprising that things like this happen," said Ariane Rummery, a spokeswoman for the UN refugee agency.

The agency has registered some 150,000 people fleeing the latest fighting. Pakistani and UN officials say the total number displaced may reach half a million.