A report by the Chinese news agency Xinhua said the drone fired four missiles at a compound suspected to be militant hideout. The area is in Eissu Khel village in the Mir Ali area of the tribal region near the border with Afghanistan.
The compound was destroyed but the identities those killed weren't immediately known.
Xinhua said it was the second such strike in the area since Tuesday, when missile attacks killed three suspected militants, including an al-Qaida-linked operative.
The Thursday action brought to at least 40 the number of suspected militants killed by drones in 2013, Xinhua said.