At least 15 people were killed while eight others were injured in an armed clash between two rival groups in Orakzai Agency on Saturday morning.
According to sources, two insurgents groups resorted to firing in Saifal Darrah and Shkar Tangi area of Upper Orakzai Agency.
Heavy artillery was used from both sides for hours that left 15 people dead and eight injured.
Death toll is expected to rise as some injured are said to be in critical condition.