Pakistani police say militants ambushed a pro-government citizen's group in Bannu district Thursday, killing nine people, including tribal elders.
Authorities say gunmen ambushed the group as it was traveling by car to meet security officials in a nearby village.
No one has claimed responsibility for the attack, but officials say the tribal elders killed had opposed the Taliban in the region. Several of their associates also were injured.
The ambush followed a separate attack that killed two members of another anti-Taliban citizen's group in the Swat Valley.
Local officials say the attackers struck overnight as the members slept.
The Pakistani government has encouraged the formation of such groups, known as lashkars, as a way to combat the Taliban in the volatile areas of northwestern Pakistan.
Former chief minister of the North West Frontier Province, Akram Khan Durrani, criticized the government's use of lashkars in an interview with VOA.
The opposition lawmaker said such groups divide local communities, making it impossible for the government to maintain peace.
Meanwhile, Pakistani military officials said their forces killed eight militants near Swat. Two security members were reported injured.
In late April, Pakistan launched a major offensive in and around Swat to stop Taliban advances in the northwestern mountainous valley.
The military still faces pockets of resistance in the area, but officials say the arrests of top Taliban leaders and the deaths of nearly 2,000 militants have helped decrease the number of recent attacks.