U.S. drone-fired missiles killed four suspected militants Monday close to the Afghan border, Pakistani officials said.
The missiles hit a vehicle close to the town of Mir Ali in the North Waziristan tribal region, which is effectively under the control of al-Qaida and Taliban militants, many of whom fight U.S. forces in Afghanistan.
The identities of those killed were not known, said the officials, who spoke on condition of anonymity because they were not authorized to brief reporters.
American drones routinely fire missiles at al-Qaida and Taliban militants on the Pakistani side of the border with Afghanistan.
U.S. officials do not talk about the CIA-led program, which is unpopular in Pakistan.
Pakistani authorities formally protest, but the army is believed to provide intelligence for some of the strikes.
Human rights groups have questioned the legality of the attacks and pointed to reports of civilian casualties, which they say are not transparently investigated, if at all.