Rockets fired from a US drone killed 15 people in northwest Pakistan today, intelligence officials said.
The attack is likely to add to tensions between Washington and Islamabad amid a standoff over NATO supply routes to Afghanistan.
The strike, the third in three days, targeted a militant hideout in the Hesokhel village of the North Waziristan tribal region, officials said.
It brought the death toll from drone attacks in Pakistan in the past three days to 27. Pilotless US drones hit targets in the South Waziristan tribal region over the weekend.
The United States and Pakistan are deadlocked in difficult negotiations for the reopening of overland supply routes to NATO forces in Afghanistan. No breakthrough is in sight.
Islamabad blocked the routes in November 2011 after 24 Pakistani soldiers were killed by cross-border "friendly fire" from NATO aircraft.
The supply lines through Pakistan are considered vital to the planned withdrawal of most foreign combat troops from Afghanistan before the end of 2014.
The Pakistan government says the CIA drone campaign fuels anti-American sentiment in the country, and is counterproductive.
US officials, however, say such strikes by the remotely piloted aircraft are highly effective against militants and are an important weapon.