Pakistan's military says 34 "terrorists" were killed "in precise aerial strikes" in the northwest of the country, near the mountainous border with Afghanistan.
The military added in a statement that the incident occurred in Tirah, Khyber Agency.
A unnamed security official said those killed belonged to the outlawed militant groups Tehrik-e-Taliban Pakistan and an allied group, Lashkar-e-Islam.
The Pakistani Taliban are allied with the Afghan militants of the same name, but they operate as a separate entity.
Officials said there were strong indications that the leader of the Pakistani Taliban, Maulana Fazlullah, was in the area at the time.
Tribal sources put the number of those killed in the strikes at 20, Reuters news agency reported.
They said most residents had already fled the area.