US missiles have killed 23 suspected militants in an attack on a compound in a tribal region near the Afghan border.
The two strikes were the fourth and fifth of the week, and the latest sign that the US has no intention of abandoning the tactic despite public disapproval in Pakistan and a downturn in relations between Islamabad and Washington following the American raid that killed Osama bin Laden.
The strikes occurred within minutes of each other, Pakistani intelligence officials said.
One missile hit a vehicle carrying five men, while the other struck a nearby compound, killing 18 people in the Shawal area, which lies along the border that separates the South and North Waziristan tribal regions.
Both regions are home to myriad militant groups, including several involved in attacks on Western forces across the border in Afghanistan.
The area hit was on the North Waziristan side, in territory under the control of Hafiz Gul Bahadur, a warlord involved in the Afghan fight.
North Waziristan is the usual target for US missiles, usually fired by unmanned Predator drones, because it is home to more groups fighting in Afghanistan and because the Pakistani military has resisted US appeals to launch an offensive there. But the strikes this week have mostly hit South Waziristan or along the border of the two regions.
Since 2008, the US has increased its use of drone-fired missiles to take out al Qaida and Taliban targets in Pakistan. Islamabad officially protests over the strikes as violations of Pakistan's sovereignty, but it is widely believed to have secretly provided intelligence for some of them.