KHAR, Pakistan - About 300,000 desperately poor villagers impoverished by fighting in Pakistan's tribal belt are scrambling to feed themselves after a female suicide bomber killed 45 people outside a World Food Program food-distribution center, triggering a districtwide suspension of the relief project.

Pakistan says the attack is a sign of insurgent desperation, but the bombing and ongoing battles challenge Islamabad's claims of victory over al-Qaeda and the Taliban in this part of the porous northwest border.

WFP district coordinator Shahab Khan said Sunday that all four food-relief centers run by the U.N. agency in the Bajaur district had been shut indefinitely because of Saturday's bombing in the area's main town of Khar.

The WFP project in Bajaur feeds 41,000 families - 300,000 people - who returned to the district from camps for the displaced elsewhere in the country, even though their livelihoods have been ruined by fighting between Pakistan troops and insurgents.

Painda Khan, 48, a farmer who abandoned his crops months ago, said his family of 11 was desperate for its rations of rice, flour, lentils, cooking oil, and high-energy biscuits that he had been going to pick up Monday.

"We have been borrowing food from neighbors for the last five days," said Khan, adding that his family last received supplies Nov. 25.

Gul Karim Khan, 53, who provides for a family of 10, also found himself robbed of options by the supply centers' closing. "We don't have any idea what we will do in the days ahead if we don't get aid," he said.

While food-relief centers outside Bajaur are still functioning, WFP official Amjad Jamal said the displaced villagers were not eligible for food rations from outside the district.

"We are trying to resume supplies at the earliest possible opportunity," Jamal said. "We are most concerned for the children in these areas, because the majority are already malnourished."

Bajaur and other parts of the tribal regions are of major concern to the United States because they have been havens for extremists fighting NATO and U.S. troops across the border in Afghanistan. The United States has long pressured Pakistan to clear the area of insurgents.

Prime Minister Yousuf Raza Gilani maintained that Pakistan's military had routed al-Qaeda and Taliban from their strongholds in the area despite the bombing and gun battles in recent days.

Coordinated attacks by 150 Islamic extremists on five security posts in the Mohmand tribal region on Bajaur's southern boundary sparked two days of fighting that officials say claimed the lives of 11 soldiers and 64 insurgents.

Gilani said the Bajaur bombing demonstrated the insurgents' weakened state.

"Their strongholds are finished . . . and they are on the run," Gilani said in the central city of Multan. "They are now turning toward soft targets like you have seen."

Khar administrator Sohail Khan said authorities had yet to identify the bomber.

The bombing, for which the Pakistani Taliban claimed responsibility, drew swift condemnation from around the world, including from President Obama. He said in a statement, "Killing innocent civilians outside a World Food Program distribution point is an affront to the people of Pakistan and to all humanity."