Pakistani warplanes pounded a militant tunnel network in a tribal region bordering Afghanistan, killing 20 Taliban insurgents, local security officials said on Wednesday.
The air strikes happened in the troubled district of Bajaur, where a major army operation launched in August has killed more than 800 people, most of them militants and displaced 300,000 civilians.
"At least 13 people were killed in repeated raids overnight in Rashakai, Khazana and Takhata towns where the militants had underground tunnels," a local security official said on condition of anonymity.
"The bombing was very heavy and planes carried out repeated sorties" until dawn on Wednesday, residents said.
Local officials said attacks resumed on Wednesday morning in two other towns in Bajaur, killing another seven militants.
Islamabad has come under intense pressure from Washington to crack down on Taliban and Al-Qaeda militants who have created safe havens in Pakistan's troubled tribal regions along the Afghan border.