Two soldiers lost their lives and 11 others suffered injuries in attacks on checkposts and security convoys.
According to sources, militants attacked a checkpost in Khershah area of central tehsil on Monday.
One soldier, Sajawal, was killed and Nazim Khan injured.
Troops backed by tanks and artillery launched a counter-attack and according to official sources 20 militants were killed and seven injured.
Civilians are fleeing the areas and moving to relief camps in Hangu and Kohat.
Clashes were also reported from Dabori where eight militants were killed and 10 injured. Four soldiers also suffered injuries.
Security forces claimed that in another clash in the same area on Sunday night 19 militants were killed and 25 injured. Six soldiers also suffered injuries.
There are reports that 25 militants were captured.
