Four missiles fired by two suspected US pilotless aircraft hit a house in Pakistan's tribal region of North Waziristan on the Afghan border on Friday, killing 25 militants, Pakistani intelligence officials said.
The drone strike happened in Mir Ali, a town about 35 kilometres (20 miles) east of the region's main town of Miranshah.
An intelligence official in the region, who requested not to be identified, told Reuters that the house was being used as a militant hideout.
"They (the militants) have surrounded the area where the attack happened and are not allowing anybody to go there," he said, adding 25 bodies had been recovered from the rubble and three women were among those killed.
Another official said some foreign militants were among the dead, but that their numbers and nationalities could not confirmed.
The strike came two days after a visit to Islamabad by Admiral Mike Mullen, the top US military official, in which he expressed concern over continuing links between Pakistan's main intelligence agency, the ISI, and militants attacking US-led forces across the border in Afghanistan.
North Waziristan is a known sanctuary for al Qaeda and Taliban militants near the Afghan border.
The United States has been using drone attacks to target al Qaeda-linked militants over the past few years in Pakistan's lawless tribal areas, a source of concern for the Pakistan government, which says civilian casualties stoke public anger and bolster support for militancy.