Officials say Pakistani troops backed by helicopters have killed 28 suspected insurgents near the Afghan border.
Thursday's strikes in Orakzai tribal region and neighboring areas are aimed at flushing out Pakistani Taliban insurgents who had fled an army onslaught further south.
Government official Sami Ullah says 18 militants died in clashes with troops in Orakzai.
Military commander Lt Col Akbar Butt says helicopters destroyed three vehicles carrying Taliban between Orakzai and Kurram regions, killing 10.
Orakzai is a major base for supporters of Hakimullah Mehsud, the Pakistani Taliban's top commander, who is believed to have died in a January US missile strike. The Taliban deny Mehsud is dead.