A car bomb destroyed an Internet cafe and tore through a bus carrying handicapped children in northwestern Pakistan on Saturday, killing at least 11 people and wounding many more, police said.

Elsewhere in the troubled region, an apparent U.S. missile strike hit a Taliban training camp, killing 29 militants, while Pakistani troops killed dozens of Taliban in their bid to re-conquer the Swat Valley, officials said.

Violence is engulfing Pakistani territory along the Afghan border as American and allied forces crank up the pressure on Al Qaeda and Taliban militants entrenched in the forbidding and barely governed mountains and valleys.

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Washington and other nations are pouring in billions of dollars in aid and military assistance to prop up the pro-Western government in Islamabad, which on Saturday sought to allay concerns that its nuclear weapons could fall into extremist hands.

The car bomb devastated a street in the main northwestern city of Peshawar on Saturday afternoon as it was busy with shoppers, traffic and worshippers heading to mosques to pray.

Television images showed several vehicles burning fiercely and a stricken white-and-green bus that had been dropping handicapped children at their homes around the city.

All eight students still on board were injured, one seriously, along the driver and an assistant, medics and police said. Four other children and seven adults were killed, and dozens more were injured, they said.

Safwat Ghayur, a senior police official, said one of a string of shops wrecked by the blast was an Internet cafe — a favorite target for violent Islamist extremists in Pakistan who consider the Web a source of moral corruption.

Ghayur said the cafe had received several threats and even been attacked recently by gunmen. He said police were holding suspects in the shooting, but refused to elaborate.

It was unclear if any of the victims had been in the cafe or if it was the intended target. No group immediately claimed responsibility.

Militants have vowed to carry out a constant stream of attacks in Pakistan in retaliation for dozens of American missile attacks on their strongholds in Pakistan's tribal areas.

In the latest strike, Pakistani officials said several missiles hit a religious school and a nearby vehicle on Saturday morning near Mir Ali, a town in the North Waziristan tribal region.

Two intelligence officials, citing reports from agents in the field, said 29 people were killed, including four foreign militants, and dozens more were wounded.

The identity of the victims was not immediately clear, the officials said. They spoke on condition of anonymity because they were not authorized to speak publicly to the media.

However, they said the school was being used as a training camp by Gul Bahadur, a prominent Taliban commander believed to be involved in fighting U.S. troops in Afghanistan.

President Barack Obama has identified the elimination of militant sanctuaries in Pakistan as critical if America is to crush Al Qaeda and turn around its faltering war effort in Afghanistan.

American officials say missile strikes, launched from remotely piloted aircraft, have killed a string of Al Qaeda commanders in the Pakistani border region over the past year. The area is considered the likely hiding place of Osama bin Laden.

However, Pakistan's government publicly protests the tactic, arguing it kills too many civilians and undermines efforts to turn tribal leaders away from hard-liners. The army this week rejected media reports that it was jointly controlling U.S. drone missions over Pakistan. The civilian government has asked Washington to add drones to its latest military aid package.

Further north, the army was preparing to assail Taliban militants entrenched in Mingora, the main town in the Swat Valley, from where nearly a million civilians have fled a three-week-old military offensive. About 100,000 are housed in sweltering camps south of the war zone.

The army says it has killed more than 800 of the estimated 4,000 militants in the valley and that many more have fled, some after shaving off their beards to blend in with the refugees.

Army spokesman Maj. Gen. Athar Abbas said Saturday that 47 militants had been killed in the previous 24 hours and that one pocket of the valley near the town of Khwazakhela was safe enough for residents to return.

Militants had blocked roads around Mingora to hamper troops encircling the town, he said at a news conference.

The military says it is advancing slowly in Swat to limit civilian casualties. Public opinion appears to support the offensive, but the mood could quickly turn against the pro-Western government if the fighting drags on and civilian hardship mounts.

The government is also trying to counter speculation that extremists could seize Pakistan's nuclear weapons or that the U.S. might intervene to safeguard them.

Prime Minister Yousuf Raza Gilani complained Saturday about an "orchestrated campaign" to "discredit Pakistan's nuclear capability."

"We are determined to retain nuclear deterrence at all cost while ensuring fail-safe security of our nuclear assets," Gilani told lawmakers, according to a statement from his office. "No amount of coercion, direct or indirect, will ever force Pakistan to compromise on its core security interest."

He didn't identify those involved in the campaign.