As fighting raged in the NWFP on Saturday, a suspected car-bomb attack in Peshawar, the province's main city, killed at least 11 people and wounded about 30 others, news agencies said.
Four children and two women were among the victims, Sifwat Ghayyur, Peshawar's police chief, said.
Imran Khan, Al Jazeera's correspondent in Peshawar, said: "It goes to show how dangerous the situation is, not only in the areas where the Taliban is being fought, but across Pakistan.
"We have talked to civilians and military and political analysts and their biggest fear has always been the aftermath if the army went into Swat valley - obviously that [army assault] has happened [in Swat].
"The big fear was a wave of [retaliatory] suicide bombings."
The United Nations said fighting between the army and Taliban had forced about 1.5 million people to flee their homes since May 2, in addition to 550,000 people already displaced by previous violence.
Many of those displaced as a result of the army offensive against the Taliban have fiercely criticised the Pakistan government.
"The government should give us peace. We have no need for tents, for food or for money. Give us peace and give us our homes," Hayat Ullah, a grandfather who fled Mingora with his wife, daughters and children, said.
Speaking from a government-run Jalala camp in Mardan, a town in NWFP, he said: "We didn't come here because of the Taliban, we came here after the shelling and bombardment of the government."
The military says that it has killed more than 940 suspected Taliban fighters since April 26 in the NWFP's districts of Lower Dir, Swat and Buner.
But there is no independent confirmation of the figures and no word on civilian casualties.
About 15,000 troops are in Swat as part of the government's attempt to rout an estimated 4,000 Taliban fighters.
The army says its troops have encircled Mingora, where Taliban fighters are believed to be hiding.
The Taliban had in recent weeks tried to enforce their version of sharia (Islamic law) across large parts of the NWFP.
The military assault against the Taliban comes after Barack Obama, the US president, said he would make focus Pakistan and Afghanistan the focus of US foreign policy.
John Kerry, the US senator and chairman of the Senate Foreign Relations Committee, told Al Jazeera that Pakistan had taken some positive steps in recent months.
"First of all, there is the first peaceful transfer of the presidency in [Pakistan's] history, at the ballot box, from one sitting president to a new president that was elected by the people," he told Al Jazeera.
"[There have been] early difficulties in the government getting its footing; that is natural when Pakistan has had a military-run government over the course of the last eight years.
"I think there are signs that [Islamabad is] taking seriously the nature of the insurgency and that they will address the question of better governance, putting services in place that reach the people."