Islamabad had encouraged tribal leaders in the region to form militias to help control the growing influence of the Taliban along the border.
In recent clashes, around 150 members of a tribal militia in the North-West Frontier province took on Taliban insurgents, killing as many as 23, the online Long War Journal reports.
The tribal militias, however, are reluctant to accept government or military support, leaving themselves vulnerable to sustained Taliban attacks. Meanwhile, a lack of regional coordination and challenges from the local geography make any tribal effort to drive out the Taliban difficult at best.
While the tribes have claimed modest success in fights against the Taliban, the militias are "losing steam," officials told the Journal.
Furthermore, the Journal notes, the recent fighting between tribal militias and members of the Pakistani Taliban undermine claims by the Pakistani government that the region is "under the control of law enforcement agencies."
Meanwhile, al-Qaida leader Ayman al-Zawahiri in an audio message released Wednesday called on Pakistanis to support Islamic militants in their fight against the United States or face punishment from God.