Hundreds have been killed in drone attacks in the past year
Three suspected militants have been killed in the third US drone strike on Pakistan's tribal district of North Waziristan in two days, officials say.
At least 12 suspected Taliban members were killed on Thursday in two attacks which correspondents say were among the most deadly of recent air strikes.
The latest attack was on a village in the Dattakhel region close to North Waziristan's main town of Miran Shah.
There have been numerous strikes by US drones in the area recently.
"The US drone missiles hit a house in the mountains," an intelligence official based in Miran Shah told the AFP news agency.
"We have reports of three militants killed and five injured. The house was completely destroyed."
Correspondents say that it is not clear what groups were targeted in the latest strike, which took place in a region believed to harbour many Taliban and al-Qaeda fighters. It is an area which has seen only limited airstrikes in the past.
North Waziristan adjoins South Waziristan, where Pakistani troops have recently concluded an ambitious offensive against the Taliban.
There have been about 60 drone strikes since August 2008, which have killed about 628 people. Critics say that many of the dead are civilians.
The US military does not routinely confirm drone attacks.
But the Obama administration has made no secret of its desire for Islamabad to stamp out militant groups who cross the porous border from the tribal belt into Afghanistan.
Pakistan has publicly criticised drone attacks, saying they fuel support for the militants.