The clashes erupted Friday in the Khyber area of northwestern Pakistan, Geo TV reported.
Thousands of residents have been displaced by the battles between groups identified as Ansarul Islam and Tehrik-e-Taliban Pakistan.
Authorities said the fighting began when TTP militants launched a mortar and rocket attack on the Ansarul Islam members in a valley located in the Tirah region, capturing five AI positions.
The head of AI, in a radio broadcast, called for supporters to help retake the positions. Hundreds of local tribesman and volunteers then assembled and launched a counterattack.
After an 8-hour fight, AI forces reclaimed four of the positions, they said.