Fighting between Taliban militants and troops in a northwestern valley triggered an exodus the government said Tuesday could see 500,000 people flee and signaled the end of a peace deal in the area widely criticized as a surrender to the extremists.
Hundreds have already fled the Swat Valley, adding to the hundreds of thousands of existing refugees driven from other regions in the northwest over the last year by fighting between soldiers and insurgents, witnesses said.
The deteriorating situation in the valley came as Pakistan's leader prepared for talks in Washington with President Barack Obama on how to sharpen his country's fight against Al Qaeda and the Taliban, which are blamed for attacks in both Pakistan and Afghanistan.
U.S. officials said Obama would seek assurances from President Asif Ali Zardari that his country's nuclear arsenal was safe and that the military intended to face down extremists in coordination with Afghanistan and the United States.
Although the administration thinks Pakistan's nuclear weapons are secure for now, concern that militants might try to seize one or several of them is acute. The anxieties have heightened amid the Taliban's recent advances and American worry about the commitment from Pakistan's government and military in battling the extremists, the officials said.
Pakistan agreed to a truce in the Swat Valley and surrounding districts in February after two years of bloody fighting with militants in the former tourist resort. It formally introduced Islamic law last month in the hope that insurgents would lay down their arms, something they have not done.
Last week, the insurgents moved from the valley into Buner, a district just 60 miles from the capital, triggering alarm at home and abroad. The army responded with an offensive that it says has killed more than 100 militants, but has yet to evict them.
On Tuesday, Khushal Khan, the top administrator in Swat said Taliban militants were roaming the area and laying mines.
A witness in the main town of Mingora said black-turbaned militants were deployed on most streets and on high buildings, and security forces were barricaded in their bases. Another reported heavy gunfire for much of the day. Both asked for anonymity out of fear for their life.
Taliban spokesman Muslim Khan said the militants were in control of "90 percent" of the valley and said their actions were in response to army violations of the peace deal such as attacking insurgents and boosting troop numbers in the region. He accused the government of acting under pressure from the U.S.
"Everything will be OK once our rulers stop bowing before America," he told The Associated Press by cell phone, adding the peace deal had "been dead" since the operation in Buner.
Khushal Khan said authorities were lifting a curfew so people could leave Mingora, and a camp had been set up for the displaced in the nearby town of Dargai. Hundreds were leaving the city, according to an AP reporter in the town.
"We are leaving the area to save our lives," said Sayed Iqbal, a 35-year-old cloth merchant who was putting household goods in a pickup truck already loaded with his elderly parents, wife and two children. "The government has announced people should leave the area. What is there left to say?"
Mian Iftikhar Hussain, the information minister for the North West Frontier Province, said up to 500,000 people were expected to flee the valley. He said authorities were releasing emergency funds and preparing six new refugee camps to house them.
Washington, which says eliminating militant havens in Pakistan is vital to winning the war in neighboring Afghanistan, has criticized the deal and called for tougher action.
While an army offensive would be welcomed abroad, it was far from certain the government would be able to dislodge the militants, who have had three months to rest and reinforce their positions.
Pakistan has waged several offensives in the border region in recent years that have often ended inconclusively amid public anger at civilian casualties. The country's army, trained to fight conventional battles against rival India, is not used to guerrilla warfare.
Pakistan is struggling to thwart an increasingly overlapping spectrum of extremist groups, some of whom have enjoyed official support. Few extremist leaders are ever brought to justice.
Also Tuesday, the High Court in the southern city of Karachi upheld an appeal by two men sentenced to death for the 2002 slayings of 11 French nationals and four other people in a bombing outside the city's Sheraton Hotel.
The judges said they suspected that the confession of one of the men, Asif Zaheer, was "not voluntary" and that prosecution witnesses had been "set up" by authorities, said state prosecutor Saifullah, who goes by only one name.
Authorities were considering appealing the acquittal, Saifullah said.
Earlier Tuesday, a suicide bomber rammed a vehicle carrying troops near Peshawar, the capital of North West Frontier Province, killing one paramilitary soldier and four civilians, police official Ghafoor Khan Afridi said. Another 21 people, including 10 troops and police and two children, were injured, Afridi said.
Pakistani militants have threatened a campaign of suicide blasts in retaliation for U.S. missile strikes on Al Qaeda and Taliban strongholds into Pakistan's northwest and for a string of military operations by government forces.