Two American missile attacks killed 15 people in north-west Pakistan today.
The region has seen few such strikes in the past, Pakistani officials said, possibly signalling an expansion of the CIA-led covert war inside the country.
The missiles, fired by unmanned drones, hit houses in the villages of Spin Drag and Shandana in the Tirah Valley of the Khyber region.
The same valley, which is known to be home to Islamist militants, was hit late on Thursday in another US attack.
US officials do not acknowledge firing the missiles. In the past, there have been occasional attacks in rarely hit areas of the border region, including at least one in Khyber.
One Pakistani official said the Khyber strikes were targeting Lashkar-e-Islam, a Taliban-affiliated network. The Pakistan army has fought the group this year, and officials have also reported its members have battled a rival extremist group in the region.
Most of the more than 100 missile attacks this year inside Pakistan have taken place in North Waziristan, which is effectively under the control of a mix of Taliban, al Qaida and related groups.
US President Barack Obama has urged Pakistan to do more in tackling extremists in the border lands. Pakistan’s army has moved into several tribal regions over the last two years, but says it lacks the troops to launch a North Waziristan operation soon.
Also today, police said nine people were killed by mortar rounds fired by suspected Sunni extremists in two attacks in the north-west.