Most of those killed in the strike on Saturday were Taliban from Punjab, the official said. He spoke on the condition of anonymity because he was not authorized to talk to the news media.

The Pakistani military, which began its operation in North Waziristan on June 15, says it has lost 26 men in the fighting, including two officers. It estimates that 400 militants have been killed.

Violence has also escalated elsewhere. Late Friday night, militants killed eight paramilitary security personnel in an attack on a vehicle in the town of Jamrud in the Khyber tribal region, near the city of Peshawar. “These are the people who have fled the operation in North Waziristan and have taken shelter here,” a senior government official said, referring to the extremists. Four police officers in Peshawar were also killed in attacks by militants on Friday.