Nine people were killed in a suspected US missile strike on a militant stronghold near the Afghan border today, Pakistani officials said.
And doctors rushed to treat an influx of wounded civilians as thousands of troops backed by bomb-dropping warplanes sought to purge Taliban militants from a north-western valley.
It was not immediately clear who the victims of the suspected US strike were.
Pakistan's leaders, encouraged by the US, launched a full-scale offensive in the Swat Valley this week to halt the spread of Taliban control in districts within 60 miles of the capital, Islamabad.
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.
Today, medics at the hospital in Swat's main town, Mingora, were at full stretch to deal with dozens of residents caught up in the fighting.
Riaz Khan, a 36-year-old schoolteacher, his wife and two daughters occupied four of the beds, the shrapnel wounds on their arms and legs covered by bandages.
Mr 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 believe al Qaida chief Osama bin Laden is 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.
US officials likened the deal to a surrender. Pakistani leaders said the agreement's collapse had opened the eyes of ordinary citizens to the extremist threat.
The army formally launched its offensive on Thursday, when Prime Minister Yousuf Raza Gilani said the government would wipe out groups trying to "take Pakistan hostage at gunpoint".
The military said yesterday that more than 140 militants and two soldiers had been killed in Swat in the last 24 hours - roughly doubling the number of casualties reported so far.
Today, an AP reporter saw jet fighters flying over Mingora and later heard explosions from further up the valley. Details of the fighting were not available.
The army said it was reinforcing the 12,000 to 15,000 troops in Swat as they take on 4,000 to 5,000 militants, including small numbers of foreigners and hardened fighters from the South Waziristan border region.
South Waziristan has been the scene of numerous suspected American missile attacks in recent months, including today's strike in the Tabai area.
Two intelligence officials said several missiles struck a disused hospital building known to be frequented by foreign militants and a tunnel in a nearby mountain, killing a total of nine militants.
The officials said field agents were still trying to determine the nationalities and names of the victims.
Pakistani leaders oppose the strikes, apparently carried out by unmanned CIA aircraft, complaining that they feed anti-American sentiment and help militants to recruit new fighters. Washington says the attacks have killed a string of al Qaida and Taliban leaders without causing mass civilian casualties.Reuse content