The US frequently uses missile attacks to hit Taliban and al-Qaeda targets in Pakistan's northwest, especially the tribal regions where many fighters are based.
This year, the vast majority of the missiles have landed in North Waziristan, a segment of the tribal belt that houses several groups of fighters.
Pakistan publicly condemns the attacks as violations of its sovereignty, and the attacks are unpopular among the Pakistani people.
But the Pakistani government is believed to assist in at least some of the missile attacks, although the US does not publicly acknowledge the existence of the covert, CIA-run operation.
In another incident, a roadside bomb in Dera Ismail Khan, which lies near the tribal belt, killed a civilian and wounded eight people, including six policemen.
Aslam Khatak, a police official, said that the attack happened as a police patrol vehicle travelled through the town.
Separately, assailiants opened fire on Saturday on a vehicle carrying Abdul Wahab, an area police chief, in the southwestern city of Quetta.
Hamid Shakeel, another police official, said that Wahab was critically wounded.