A US drone missile attack Monday killed four militants in a remote Pakistani tribal town bordering Afghanistan, officials said.
The missile targeted a militant vehicle in Toori Khel village in North Waziristan region, they said.
"Four militants were killed," a local government official said, requesting anonymity. He added the number of wounded was not immediately known.
A security official, however, said four people were wounded.
He said "two of the militants killed in the vehicle were believed to be foreigners" but details were not immediately available.
The word "foreigners" is official jargon in Pakistan for Al-Qaeda militants.
"The missile was fired from a US drone," he said.
Monday's drone strike was the third within a week in North Waziristan, where militants linked to Taliban and Al-Qaeda are said to have sanctuaries.
At least three militants were killed in a similar attack in the area last Tuesday.
Last Monday a strike targeting a madrassa (Islamic seminary) and an adjoining house killed five people.
Washington alleges Al-Qaeda and Taliban rebels who fled Afghanistan after the 2001 US-led invasion are holed up in Pakistan's semi-autonomous tribal belt.
The US military does not, as a rule, confirm drone attacks, but its armed forces and the Central Intelligence Agency operating in neighbouring Afghanistan are the only forces that deploy pilotless drones in the region.
A US drone attack on August 5 in neighbouring tribal district of South Waziristan killed Pakistan's feared Taliban warlord Baitullah Mehsud.
Pakistan's previous government accused Mehsud of masterminding the 2007 assassination of ex-prime minister Benazir Bhutto and a string of other attacks that have killed hundreds of people here over the last two years.
Islamabad publicly opposes suspected US missile strikes, saying they violate its territorial sovereignty and deepen resentment among the populace. Since August 2008, nearly 60 such strikes have killed more than 550 people.
However some analysts and observers believe that the government tacitly supports the attacks, as it shares the US goal of eliminating Mehsud's network.
Pakistan in April launched a punishing military offensive against the Taliban in the northwest, targeting the rebels in the districts of Swat, Buner and Lower Dir after militants advanced towards Islamabad.
The military claimed to have cleared the area of Taliban and vowed to turn their attention to the mountainous tribal belt along the border where Mehsud and his Tehreek-e-Taliban Pakistan (TTP) have thrived since 2007.