LONDON — An American drone struck a militant compound in Pakistan’s tribal belt for the second time in 12 hours on Thursday, killing at least 10 suspected members of the Haqqani network in a suddenly intense resurgence of the C.I.A. offensive in Pakistan.

The American drone strikes, after an almost six-month lull in the operations while Pakistani officials tried and failed to negotiate a peace deal with the Taliban, come as Pakistan is mulling a new offensive of its own against militants in the northwestern tribal belt. But early news reports on Thursday offered conflicting comments about whether the Pakistani authorities might have approved the drone strikes or worked in tandem with the Americans — a politically caustic idea in a country where the C.I.A. program is widely hated.

The strikes, both of which were reported to have killed Haqqani operatives, also came two weeks after the release of the American soldier Sgt. Bowe Bergdahl, who had been a hostage of the Haqqanis for five years. A former American military commander has suggested that Sergeant Bergdahl’s safety will give the United States more freedom to strike at the Haqqanis, who are fighting to overthrow the American-backed civilian government in Afghanistan.

Pakistani security officials said Thursday that a C.I.A. drone had fired six missiles at the compound four miles north of Miram Shah, the main town in North Waziristan. The attack, which occurred just after 2 a.m. on Thursday, targeted a building and an explosives-laden truck parked outside, they said.