There have been frequent drone attacks in recent months
At least four people have been killed by a suspected US drone missile in Pakistan's North Waziristan region, Pakistani security officials say.
The attack targeted a suspected militant compound in the Dandey Darpa Khel area.
The high-profile insurgent commander, Jalaluddin Haqqani, is thought to be active in the area.
His Pakistan-based network is blamed for a string of attacks on the Afghan government and foreign forces.
Harsh living conditions
North Waziristan has seen frequent attacks from US drone missiles targeting al-Qaeda and Taliban insurgents.
The US does not generally confirm any missile attacks by drones.
Pakistan has regularly said that the attacks are a violation of its sovereignty.
In one high-profile attack in August, Taliban leader Baitullah Mehsud was killed.
BBC security correspondent Frank Gardner says the drone attacks are believed to be having a dramatic effect on al-Qaeda's core leadership in north-western Pakistan.
Senior British government officials believe that a combination of harsh living conditions in Pakistan's tribal territories and relentless pressure from the drones is having a disruptive effect on al-Qaeda's ability to plan attacks and train new recruits.
Our correspondent says that since January last year at least 13 senior al-Qaeda leaders are reported to have been killed by the strikes.
However, he says the global jihadist movement has proved itself adept at surviving and adapting to rapidly changing circumstances.