At least 21 people, believed to be Pakistani militants, have reportedly been killed in two separate attacks by an unmanned US drone aircraft in north-west Pakistan.
Pakistani security officials say the missiles struck targets in the North Waziristan tribal region near the Afghan border.
Pakistan has previously complained that such attacks violate its sovereignty.
Last month, US President Barack Obama defended the use of drones to target militants in Pakistan's tribal areas.
The area of the recent attacks is known as a sanctuary in Pakistan for the Taliban and al-Qaeda-linked militants.
The attacks come a week after officials said one of the most senior al-Qaeda militants in Pakistan, Badar Mansoor, was killed in a US drone strike.