Pakistani security forces Friday attacked suspected militant hideouts with helicopter gunships and mortar fire in a tribal region near Afghanistan, the army said.

The offensive marked an escalation in the conflict in Bajur, where militants attacked a checkpost Wednesday. Officials said the ensuing clash killed 25 militants and two troops.

Maj. Gen. Athar Abbas confirmed the offensive, saying army helicopters were supporting paramilitary ground troops.

Residents in Bajur’s main town of Khar reported seeing helicopter gunships flying overhead and heard the sound of mortar fire.

Pakistani Taliban spokesman Maulvi Umar claimed only two militants were killed this week.