Taliban spokesman Maulvi Umar said the attack in Peshawar was retaliation for recent military operations in the border region near Afghanistan. "It is an open war between us and them," he told the Associated Press.
"We have done it in reaction to the government operations in Swat and Bajur," Umar said. "If this kind of operations continue against us in Swat and in the tribal areas, we will continue this."
Provincial government spokesman Mian Iftikhar Hussain told news agencies that 14 people were killed in the truck blast, mostly air force personnel, and more than 12 people were wounded, although media reports differed as to the number of military personnel and civilians killed.
The powerful blast destroyed the truck as well as two nearby cars as they passed over a bridge. A 5-year-old girl in a passing car was among the dead civilians, Nisar Khan, a Peshawar police officer, told the AP.
The police chief of North-West Frontier Province, Malik Naveed Khan, told the Agence France-Presse the bomb appeared to have been remotely detonated.
"So far, according to my information, it was a security vehicle and an IED (improvised explosive device) was planted under the bridge," Khan told the AFP.
Pakistani army spokesman Maj. Gen. Athar Abbas said recent fighting in Bajur, an area near the Afghan border known as a militant hot spot, has killed at least 150 militants in the past week. Officials reported that at least nine troops died.
Thousands of residents have reportedly left to avoid the fighting.
Pakistan has faced ongoing pressure from the West to root out Taliban and al-Qaida operatives holed up along the Pakistan-Afghan border.
Pakistani officials have sought peace deals in the border region in hopes of controlling Islamic militants who have been blamed for a wave of suicide attacks across the country in the past year.
Meanwhile, reports emerged Tuesday that Abu Saeed al-Masri, a reported top al-Qaida commander, had been killed in clashes with Pakistani forces in the volatile border region.
"He was believed to be among the top leadership of al Qaeda," a senior security official told Reuters on condition of anonymity.
Al-Masri, also known in media reports as Mustafa Abu al-Yazid, was an Egyptian who served time in jail with al-Qaida deputy leader Ayman al-Zawahri after the assassination of Egyptian President Anwar Sadat in 1981.
The 9/11 Commission described Abu Saeed al-Masri as the network's "chief financial manager" during the course of its findings.
If confirmed, al-Masri's death would mark the most senior al-Qaida operative to have been killed in Pakistan's tribal belt since last month's death of Abu Khabab al-Masri, a chemical and biological weapons expert, Reuters reported.