Pakistani air strikes on Wednesday killed 34 militants in the lawless northwest of the country, near the mountainous border with Afghanistan, security officials said, but tribal residents put the toll at 20.
Fighter jets pounded positions in the Tirah Valley in the Khyber tribal region, west of the city of Peshawar, in "precise" strikes", the military said in a statement.
"The local population had fled their homes and villages when the operation was launched against the terrorists there," an official told Reuters.
Another security official said those killed belonged to the outlawed militant groups Tehrik-e-Taliban Pakistan and an allied group, Lashkar-e-Islam.
"In precise aerial strikes in Tirah, Khyber Agency, 34 terrorists were killed today," the military said in a statement.
The Pakistani Taliban are allied with the Afghan militants of the same name and share a similar jihadist ideology. But they operate as a separate entity, focussed on toppling the Pakistani state and establishing strict Islamic rule in the nuclear-armed nation.
The officials said there were strong indications that the leader of the Pakistani Taliban, Maulana Fazlullah, was in the area at the time.
Tribal sources said 20 militants, among a group which had taken refuge in the valley, were killed in the air strikes.
They said most of the residents had already fled the area.
Abdur Rashid, a tribesman displaced by the fighting, said he and other tribespeople had left behind some of their family members to look after their houses and livestock.
"My elder brother said he had personally seen militants shifting bodies of the slain fighters to upper Tirah from Sandasa and nearby villages," he said by phone from the Landi Kotal subdivision of Khyber.
"Local militants of Lashkar-e-Islam told them 20 people were killed."