More than 200 militants crossed into Pakistan from Afghanistan early Thursday and attacked a border village with rockets, mortars and machine guns, killing five people and kidnapping more than 20, officials and residents said.
The deadly raid underlines challenges ahead for the U.S. and Pakistan when Washington begins withdrawing troops from Afghanistan later this year. Pakistan maintains that NATO already needs more troops along the Afghan side of the border.
On Thursday, the Pakistani military fought with the militants for roughly six hours, using helicopter gunships, said Sajid Khan, a senior government official in the Bajur tribal region. The dead included three women and two men, and eight others were wounded, he said.
The militants fled after the military brought in reinforcements and hit them with artillery fire, said local resident Asar Khan. But they kidnapped more than 20 tribesmen and took them along, he said.
It was the second such raid in just two weeks, illustrating how militants can easily move across the rugged border between Pakistan and Afghanistan.
Pakistan has complained that NATO forces in Afghanistan are not doing enough to stem the flow of militants across the border, while the U.S. says Pakistan's military must do more to stop fighters from streaming into Afghanistan.
Earlier this month, militants swarmed into Pakistan's Upper Dir district from Afghanistan, triggering fighting that lasted several days before the Pakistani military was able to force them back across the border. The government said at least 25 soldiers, 35 militants and three civilians were killed in the clashes.
Both Bajur and Upper Dir are located across the border from Afghanistan's Kunar province, large parts of which are controlled by the Taliban.
Meanwhile, NATO countries, including the U.S., suspect Pakistan is refusing to target Afghan Taliban militants and their allies holed up in the country because the government believes they could be useful allies in Afghanistan after foreign forces withdraw.
In the past, NATO and Pakistani forces have staged coordinated "hammer and anvil" operations against militants on the border, but relations between Washington and Islamabad have hit a particularly rough patch, especially since the unilateral American raid in Pakistan that killed Osama bin Laden on May 2.
Even so, NATO officials say that border cooperation has not suffered as a result of the chill in ties.