Pakistani intelligence officials say a U.S. drone strike has killed at least 20 militants in the tribal region along the Afghan border.

The officials said the unmanned aircraft fired two missiles into a house Wednesday near the town of Miranshah in the North Waziristan region.

U.S. officials do not publicly acknowledge the use of such strikes inside Pakistan but privately have confirmed their existence to various news outlets. Pakistan has condemned the attacks as a violation of its sovereignty, but the drone strikes are believed to be carried out with the help of Pakistani intelligence.