The Pakistani Taliban declared "open war" Tuesday in response to military offensives in the northwest, saying it staged a bombing that destroyed an air force truck and killed up to 14 people, including a child.

Authorities, meanwhile, investigated whether an insurgent reported killed in one of the military operations was a senior Al Qaeda commander. The offensive in the Bajur tribal area reportedly has killed 160 people and caused tens of thousands to flee to camps farther north.

The blast in Peshawar, the main city on the restive frontier with Afghanistan, escalated the conflict in a region where the new government is struggling to contain increasingly brazen militants. It dealt another blow to efforts to strike peace deals with hard-liners in the Swat Valley and other areas, pacts that U.S. officials contend would strengthen extremists.

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"It is an open war between us and them," Pakistani Taliban spokesman Maulvi Umar told The Associated Press. "If these kinds of operations continue against us in Swat and in the tribal areas, we will continue this."

Pakistani officials could not be reached for comment or declined to react to the Taliban's statement, but earlier in the day Interior Ministry chief Rehman Malik said the country would not yield in its attempts to end militancy in its frontier areas.

"It is our firm resolve that we will root out terrorism from Pakistan, and all of our security agencies are working together to achieve this goal," he told the AP.

The bomb hit the air force truck as it crossed a bridge on the outskirts of Peshawar. The blast tore a big hole in the bridge deck and reduced the Mazda truck to a smoldering wreck. The site was littered with debris, blood and a mangled motorcycle.

A provincial government spokesman, Mian Iftikhar Hussain, said the explosion killed 14 people, most of them air force personnel, and wounded more than a dozen.

An air force statement put its death toll at five airmen, two lower-ranking personnel and two civilian employees. Five air force personnel also were wounded, it said.

A 5-year-old girl in a nearby vehicle was among those killed, said Nisar Khan, a Peshawar police officer. He said police were trying to trace her relatives.

A bomb disposal officer, who requested anonymity because he was not authorized to speak to journalists, said the bomb had been attached under the bridge and contained between 66 and 88 pounds (between 30 and 40 kilograms) of explosives.

President Pervez Musharraf condemned the blast in a statement that said he "reiterated the resolve of the nation to remain determined and not yield to pressures created by such heinous crimes."

The increasingly unpopular Musharraf faces possible impeachment by the governing coalition that came to power after February elections. Many Pakistanis blame his alliance with Washington after the Sept. 11 attack on the U.S. for rising militancy in the country.

U.S. officials have anxiously watched the new government's effort to grapple with militant movements by using both sticks and carrots. Of particular concern to the West is the government's weak hold on the tribal regions, which are considered Taliban and Al Qaeda strongholds.

NATO contends cease-fire deals have allowed militants based in the frontier areas to step up attacks across the border in Afghanistan, while U.S. officials warn that Al Qaeda leaders hiding along the border could be plotting attacks on the West.

On Tuesday, a senior Interior Ministry official confirmed that authorities were probing the identity of a suspected militant reported killed this week during the fighting in Bajur.

A senior intelligence official identified the militant as an Egyptian known as Abu Saeed and said he was believed to be a close aide of Al Qaeda No. 2 leader Ayman al-Zawahri. He said authorities had intelligence that the militant was killed but had not found the body.

A top Al Qaeda commander in Afghanistan, Mustafa Abu al-Yazeed, who had appeared in videos issued by the terrorist network, is also known as Abu Saeed al-Masri. The ministry official said authorities were trying to determine whether the Abu Saeed reported killed was the same man.

Both Pakistani officials spoke on condition of anonymity because they were not authorized to release the information.

Contacted by the AP, two spokesmen for Afghanistan's Taliban, Qari Yousef Ahmadi and Zabiullah Mujahid, said they had no information about the reported death.

In late July, an Al Qaeda explosives and poison expert, Abu Khabab al-Masri, was killed by a suspected U.S. missile strike in the Pakistani border region of South Waziristan.

On Tuesday, Pakistani army helicopter gunships fired on suspected militant positions in Bajur, which is north of Peshawar along the rugged Afghan-Pakistan frontier.

The army spokesman, Maj. Gen. Athar Abbas, said the fighting in Bajur had killed at least 150 militants in the past week. Officials have reported at least nine paramilitary troops dead.

Independent confirmation of casualties has not been possible, but the fighting caused thousands to flee their homes in Bajur to take refuge in the nearby Lower Dir area.

Kamran Rehman Khan, a top aide to the chief minister of North West Frontier Province, said three government camps were serving some 17,500 people and a fourth was being set up. Leaders of political parties in the region said their own camps held some 45,000 people.