The area has a history of sectarian tension. A little-known militant group calling itself Lahskar-e-Jhangvi al Almi says it carried out the attack. They say the attack was in revenge for the death of a prominent religious leader. Maulana M Amin was killed in Hangu in June 2009. Correspondents say the group is likely to be linked to Lashkar-e-Jhangvi, a Sunni extremist group which has links to the Taliban. Astarzai village, where the blast took place, has a substantial Shia population and is close to the Orakzai tribal region, a stronghold of the Taliban’s present chief.

Hakimullah Mehsud took over as chief of the Pakistani Taliban – a Sunni group – after his predecessor, Baitullah Mehsud, was killed by a US missile strike.

‘People trapped’

The car bomb was detonated close to a hotel owned by a Shia Muslim businessman.

Police officials said that many people had been injured by the explosion.

Witnesses told the BBC the blast was so powerful it nearly demolished several buildings in the area.

“Dozens of shops were destroyed. Their roofs caved in and many people were trapped under the debris,” a local police official told the AFP news agency.

Television footage from the local hospital showed bloodied and bandaged patients being treated by medical staff.

“I was standing in front of my shop when all of a sudden, a car blew up outside a restaurant,” Sohail Ahmed told AFP from his hospital bed.

At the time of the explosion, the area was reported to be thronged with shoppers buying supplies for the weekend and for iftar, the break of fast during the Muslim fasting month of Ramadan.

Astarzai lies 18km (11 miles) west of the town of Kohat, where a bomb was detonated on Thursday wounding at least six people.

The BBC’s M Ilyas Khan in Islamabad says that Sunni Taliban militants in the area have carried out frequent attacks on minority Shias.

Sunni Muslims account for around 80% of Pakistan’s population and are the dominant group in the tribal areas, although Orakzai has significant Shia numbers.

Pakistan’s army has been bombing Taliban hideouts in Orakzai for the past month, correspondents say.

There were reports of more aerial bombings in the area on Friday morning, shortly before the bomb attack.

The last month has seen a series of major attacks on targets across the NWFP.

On 30 August a suspected suicide bomb attack in Pakistan’s north-western Swat valley killed at least 14 police recruits and injured others.

And in February, at least 25 people were killed when a bomb exploded at the funeral procession of a prominent Shia Muslim cleric.

Pakistani Taliban punished a man accused of impersonating one of them to extort money in Matta, in the volatile Swat Valley.

Using a portable radio transmitter, a local Taliban leader, Shah Doran, on most nights outlines newly proscribed “un-Islamic” activities in Swat, like selling DVDs, watching cable television, singing and dancing, criticizing the Taliban, shaving beards and allowing girls to attend school. He also reveals names of people the Taliban have recently killed for violating their decrees — and those they plan to kill.

“They control everything through the radio,” said one Swat resident, who declined to give his name for fear the Taliban might kill him. “Everyone waits for the broadcast.”

International attention remains fixed on the Taliban’s hold on Pakistan’s semiautonomous tribal areas, from where they launch attacks on American forces in Afghanistan. But for Pakistan, the loss of the Swat Valley could prove just as devastating.

Unlike the fringe tribal areas, Swat, a Delaware-size chunk of territory with 1.3 million residents and a rich cultural history, is part of Pakistan proper, within reach of Peshawar, Rawalpindi and Islamabad, the capital.

After more than a year of fighting, virtually all of it is now under Taliban control, marking the militants’ farthest advance eastward into Pakistan’s so-called settled areas, residents and government officials from the region say.

With the increasing consolidation of their power, the Taliban have taken a sizable bite out of the nation. And they are enforcing a strict interpretation of Islam with cruelty, bringing public beheadings, assassinations, social and cultural repression and persecution of women to what was once an independent, relatively secular region, dotted with ski resorts and fruit orchards and known for its dancing girls.

Last year, 70 police officers were beheaded, shot or otherwise slain in Swat, and 150 wounded, said Malik Naveed Khan, the police inspector general for the North-West Frontier Province.

The police have become so afraid that many officers have put advertisements in newspapers renouncing their jobs so the Taliban will not kill them.

One who stayed on the job was Farooq Khan, a midlevel officer in Mingora, the valley’s largest city, where decapitated bodies of policemen and other victims routinely surface. Last month, he was shopping there when two men on a motorcycle sprayed him with gunfire, killing him in broad daylight.

“He always said, ‘I have to stay here and defend our home,’ ” recalled his brother, Wajid Ali Khan, a Swat native and the province’s minister for environment, as he passed around a cellphone with Farooq’s picture.

In the view of analysts, the growing nightmare in Swat is a capsule of the country’s problems: an ineffectual and unresponsive civilian government, coupled with military and security forces that, in the view of furious residents, have willingly allowed the militants to spread terror deep into Pakistan.

The crisis has become a critical test for the government of the civilian president, Asif Ali Zardari, and for a security apparatus whose loyalties, many Pakistanis say, remain in question.

Seeking to deflect blame, Mr. Zardari’s government recently criticized “earlier halfhearted attempts at rooting out extremists from the area” and vowed to fight militants “who are ruthlessly murdering and maiming our citizens.”

But as pressure grows, he has also said in recent days that the government would be willing to talk with militants who accept its authority. Such negotiations would carry serious risks: security officials say a brief peace deal in Swat last spring was a spectacular failure that allowed militants to tighten their hold and take revenge on people who had supported the military.

Without more forceful and concerted action by the government, some warn, the Taliban threat in Pakistan is bound to spread.

“The crux of the problem is the government appears divided about what to do,” said Mahmood Shah, a retired Pakistani Army brigadier who until 2006 was in charge of security in the western tribal areas. “This disconnect among the political leadership has emboldened the militants.” From 2,000 to 4,000 Taliban fighters now roam the Swat Valley, according to interviews with a half-dozen senior Pakistani government, military and political officials involved in the fight. By contrast, the Pakistani military has four brigades with 12,000 to 15,000 men in Swat, officials say.

But the soldiers largely stay inside their camps, unwilling to patrol or exert any large presence that might provoke — or discourage — the militants, Swat residents and political leaders say. The military also has not raided a small village that locals say is widely known as the Taliban’s headquarters in Swat.

Nor have troops destroyed mobile radio transmitters mounted on motorcycles or pickup trucks that Shah Doran and the leader of the Taliban in Swat, Maulana Fazlullah, have expertly used to terrify residents.

Being named in one of the nightly broadcasts often leaves just two options: fleeing Swat, or turning up headless and dumped in a village square.

When the army does act, its near-total lack of preparedness to fight a counterinsurgency reveals itself. Its usual tactic is to lob artillery shells into a general area, and the results have seemed to hurt civilians more than the militants, residents say.

In some parts of Pakistan, civilian militias have risen to fight the Taliban. But in Swat, the Taliban’s gains amid a large army presence has convinced many that the military must be conspiring with the Taliban.

“It’s very mysterious how they get so much weapons and support,” while nearby districts are comparatively calm, said Muzaffar ul-Mulk Khan, a member of Parliament from Swat, who said his home near Mingora was recently destroyed by the Taliban.

“We are bewildered by the military. They patrol only in Mingora. In the rest of Swat they sit in their bases. And the militants can kill at will anywhere in Mingora,” he said.

“Nothing is being done by the government,” Mr. Khan added.

Accusations that the military lacks the will to fight in Swat are “very unfair and unjustified,” said Maj. Gen. Athar Abbas, the chief military spokesman, who said 180 army soldiers and officers had been killed in Swat in the past 14 months.

“They do reach out, and they do patrol,” he said.

Military officials also say they are trying to step up activity in Swat. This weekend, soldiers were deployed to protect a handful of educational buildings in Mingora, amid a wave of school bombings.

General Abbas said the military did not have the means to block Taliban radio transmissions across such a wide area, but he disputed the view that Mingora had fallen to the militants.

“Just because they come out at night and throw down four or five bodies in the square does not mean that militants control anything,” he said.

Few officials would dispute that one of the Pakistani military’s biggest mistakes in Swat was its failure to protect Pir Samiullah, a local leader whose 500 followers fought the Taliban in the village of Mandal Dag. After the Taliban killed him in a firefight last month, the militants demanded that his followers reveal his gravesite — and then started beheading people until they got the information, one Mandal Dag villager said.

“They dug him up and hung his body in the square,” the villager said, and then they took the body to a secret location. The desecration was intended to show what would happen to anyone who defied the Taliban’s rule, but it also made painfully clear to Swat residents that the Pakistani government could not be trusted to defend those who rose up against the militants.

“He should have been given more protection,” said one Pakistani security official, who spoke on condition of anonymity because of the delicacy of the subject. “He should have been made a symbol of resistance.”

Gruesome displays like the defilement of Pir Samiullah’s remains are an effective tactic for the Taliban, who have shown cruel efficiency in following through on their threats.

Recently, Shah Doran broadcast word that the Taliban intended to kill a police officer who he said had killed three people.

“We have sent people, and tomorrow you will have good news,” he said on his nightly broadcast, according to a resident of Matta, a Taliban stronghold. The next day the decapitated body of the policeman was found in a nearby village.

Even in Mingora, a town grown hardened to violence, residents were shocked early this month to find the bullet-ridden body of one of the city’s most famous dancing girls splayed on the main square.

Known as Shabana, the woman was visited at night by a group of men who claimed to want to hire her for a party. They shot her to death and dragged her body more than a quarter-mile to the central square, leaving it as a warning for anyone who would flout Taliban decrees.

The leader of the militants in Swat, Maulana Fazlullah, gained prominence from making radio broadcasts and running an Islamic school, becoming popular among otherwise isolated homemakers and inspiring them to sell their jewelry to finance his operation. He also drew support from his marriage to the daughter of Sufi Mohammed, a powerful religious leader in Swat until 2001 who later disowned his son-in-law.

Even though Swat does not border Afghanistan or any of Pakistan’s seven lawless federal tribal areas, Maulana Fazlullah eventually allied with Taliban militants who dominate regions along the Afghan frontier.

His fighters now roam the valley with sniper rifles, Kalashnikovs, rocket-propelled grenade launchers, mortar tubes and, according to some officials, night-vision goggles and flak vests.

His latest tactic is a ban on girls’ attending school in Swat, which will be tested in February when private schools are scheduled to reopen after winter recess. The Taliban have already destroyed 169 girls’ schools in Swat, government officials say, and they expect most private schools to stay closed rather than risk retaliation.

“The local population is totally fed up, and if they had the chance they would lynch each and every Talib,” said Mr. Naveed Khan, the police official. “But the Taliban are so cruel and violent, no one will oppose them. If this is not stopped, it will spill into other areas of Pakistan.”

Muhammad Saad Iqbal, back in Lahore, Pakistan. Released from Guantánamo in August, he has trouble walking.

In November, a Pakistani surgeon operated on his ear, physical therapists were working on lower back problems and a psychiatrist was trying to wean him off the drugs he carried around in a white, plastic shopping bag.

The maladies, said Mr. Iqbal, 31, a professional reader of the Koran, are the result of a gantlet of torture, imprisonment and interrogation for which his Washington lawyer plans to sue the United States government.

The coming administration of President-elect Barack Obama is weighing whether to close the Guantánamo prison, which many critics have called an extralegal system of detention and abuse.

But the full stories of individual detainees like Mr. Iqbal are only now emerging after years in which they were shuttled around the globe under the Bush administration’s system of extraordinary rendition, which used foreign countries to interrogate and detain terrorism suspects in sites beyond the reach of American courts.

Mr. Iqbal was never convicted of any crime, or even charged with one. He was quietly released from Guantánamo with a routine explanation that he was no longer considered an enemy combatant, part of an effort by the Bush administration to reduce the prison’s population.

“I feel ashamed what the Americans did to me in this period,” Mr. Iqbal said, speaking for the first time at length about his ordeal during several hours of interviews with The New York Times, including one from his hospital bed in Lahore.

Mr. Iqbal was arrested early in 2002 in Jakarta, Indonesia, after boasting to members of an Islamic group that he knew how to make a shoe bomb, according to two senior American officials who were in Jakarta at the time.

Mr. Iqbal now denies ever having made the statement, but two days after his arrest, he said, the Central Intelligence Agency transferred him to Egypt. He was later shifted to the American prison at Bagram Air Base in Afghanistan, and ultimately to Guantánamo Bay.

Much of Mr. Iqbal’s account could not be independently corroborated. Two senior American officials confirmed that Mr. Iqbal had been “rendered” from Indonesia, but could not comment on, or confirm details of, how he was treated in custody. The Pentagon and C.I.A. deny using torture, and American diplomatic, military and intelligence officials agreed to talk about the case only on the condition of anonymity because the files are classified.

After Mr. Iqbal was picked up in Jakarta and interrogated for two days, American officials generally concluded that he was a braggart, a “wannabe,” and should be released, one of the senior American officials in Jakarta said. “He was a talker,” the senior American official said. “He wanted to believe he was more important than he was.”

There was no evidence that he had ever met Osama bin Laden, or had been to Afghanistan, the two senior American officials said. But in the atmosphere of fear and confusion in the months after Sept. 11, 2001, Mr. Iqbal was secretly moved to Egypt for further interrogation, said one of the senior American officials.

Mr. Iqbal said he had been beaten, tightly shackled, covered with a hood and given drugs, subjected to electric shocks and, because he denied knowing Mr. bin Laden, deprived of sleep for six months. “They make me blind and stand up for whole days,” he said in halting English, meaning that he had been covered with a hood or blindfolded.

The Pentagon and the C.I.A. have a policy of not talking about the detainees, but a C.I.A. spokesman, Paul Gimigliano, said, “The agency’s terrorist detention program has used lawful means of interrogation, reviewed and approved by the Department of Justice and briefed to the Congress.

“This individual, from what I have heard of his account, appears to be describing something utterly different,” Mr. Gimigliano added. “I have no idea what he’s talking about. The United States does not conduct or condone torture.”

Mr. Iqbal said he traveled to Jakarta in November 2001 on a personal odyssey to inform his stepmother that her husband — Mr. Iqbal’s father — had died of a stroke in Pakistan.

He fell in with members of the Islamic Defenders Front, according to his statement to the combatant status review tribunal at Guantánamo in 2004. The group is an Indonesian urban-based organization. It is not banned in Indonesia and has not been connected to any terrorist attacks. According to Mr. Iqbal’s statement before the review tribunal at Guantánamo, he said he had told his new friends that he knew how to make a bomb that could be tucked into a shoe. He denies that now, saying someone else in the group made the boast.

Whatever the truth, the conversation among that circle of acquaintances caught the attention of Indonesian intelligence.

The Indonesian agents passed the information on to the C.I.A. in Jakarta, and Mr. Iqbal was seized at his rented room just before dawn on Jan. 9, 2002.

Mr. Iqbal said he had received his first round of physical abuse at the Jakarta airport, before being shoved onto the plane, shackled and blindfolded.

“One person from Egyptian intelligence, he come and he punch me here, very hard,” he said, pounding his chest, “and he grab me like this and he throw me against the wall. Then they make me naked, they torture me.”

He said he knew that his assailant at the airport was Egyptian from his Arabic accent. According to a senior American official and two Indonesian officials, Mr. Iqbal was flown from Jakarta to Cairo on a C.I.A. aircraft.

During the flight to Cairo, Mr. Iqbal said, he was bleeding from his nose, mouth and ears, and was unable to move because shackles wound tightly around his body.

When the plane landed, he was told he was in Cairo, he said. He was assigned a basement room like “a grave,” about 6 feet by 4 feet, he said, and was kept there for 92 days, according to the transcript of his tribunal hearing. On Jan. 11, 12 and 20, 2002, he was interrogated for 12 to 15 hours on each occasion, he said during the interviews here.

He described the interrogators as Egyptians. Mr. Iqbal said there were other men in the room whose faces were covered and who did not speak, but who passed notes with questions to the Egyptians.

He was asked when he had gone to Afghanistan and how he had met Mr. bin Laden. When he replied that he had never been to Afghanistan and had not met Mr. bin Laden, the Egyptians tortured him with electric shocks, he said. “I cry and I yell,” he said. “Also they gave me brain electric shocks.” He said he was forced to consume liquids that were laced with drugs “so you don’t know what you are talking about.”

In early April, he said, the Americans flew him to Bagram, the American air base outside the Afghan capital, Kabul. He was held there for almost a year, at times shackled and handcuffed in a small cage with other detainees, and further interrogated, he said.

“A C.I.A. person said, ‘We forgive you; just accept you met Osama bin Laden.’ I said, ‘No, I’m not going to say that.’ ” Even though polygraph tests showed that he was telling the truth, he said, he was shifted from cell to cell every few hours and deprived of sleep for six months.

Once he arrived at Guantánamo, on March 23, 2003, Mr. Iqbal was treated as an outcast by the other prisoners because he had not been trained in Afghanistan, according to a fellow inmate, Mamdouh Habib, an Australian who befriended him.

Mr. Iqbal became so depressed he tried to hang himself twice, and went on three hunger strikes, Mr. Habib said.

According to a statement in April 2007 by Dr. Ronald L. Sollock, the commander of the Naval Hospital at Guantánamo Bay, filed with the Court of Appeals in Washington, Mr. Iqbal was diagnosed with a perforated left eardrum, inflammation of the left external ear canal and inflammation of the left middle ear.

From 2003, according to the court filing by Dr. Sollock, Mr. Iqbal was prescribed antibiotics.

By the time he returned home to Pakistan, Mr. Iqbal was dependent on a “long list of drugs,” Mohammad Mujeeb, a professor of ear, nose and throat at the Services Hospital in Lahore, said in an interview. He said that part of Mr. Iqbal’s difficulty in walking appeared to be psychological, with scans showing only “mild to moderate” compression of the nerves in his back.

After Guantánamo, he was flown on an American military aircraft to the Islamabad airport, where two American Embassy officers, First Lt. Brian Strait and Keith Easter, witnessed his release, according to a United States government document he displayed. He was admitted to a hospital in Islamabad for treatment, and then questioned for three weeks at a safe house by Pakistani intelligence officers in what Mr. Iqbal called friendly sessions. Pakistani security officers then drove him back to Lahore and his extended family. “It was like a new life for me,” he said. “I was born again. There is no word to explain.”

Mr. Iqbal’s case is now being fought in the American courts. His lawyer, Richard L. Cys of Davis Wright Tremaine, who visited him in Guantánamo, said he planned to sue the American government for the unlawful detention of Mr. Iqbal.

Mr. Cys has also filed a lawsuit in the federal courts to win the release of Mr. Iqbal’s medical records for the period he was at Guantánamo, hoping to confirm Mr. Iqbal’s account of his abuse in Egypt.

In Lahore, Mr. Iqbal wants to return to teaching the Koran. “It’s easy for the United States to say no charges were found,” he said. “But who is responsible for the seven years of my life?”