congress has moved to block president obama ’s plan to shift control of the u.s. drone campaign from the cia to the defense department , inserting a secret provision in the massive government spending bill introduced this week that would preserve the spy agency ’s role in lethal counterterrorism operations , u.s. officials said . senior yemeni officials later admitted that the strike was a “ mistake ” . in the wake aden ( reuters ) - a yemeni farmer was killed in a u.s. drone strike on wednesday in what witnesses said was an attack apparently intended for suspected islamist militants in southeastern yemen . those apprehensions were amplified after a u.s. military strike hooria mashhour is yemen ’s minister for human rights . a u.s. cruise missile killed 41 civilians in al - majala , including 14 women and 21 children . last month , at least 15 people were killed and five others injured when a drone mistook a wedding party travelling in the central yemeni province of al - bayda for an al qaeda convoy . the provision represents an unusually direct intervention by lawmakers into the way covert operations are run , impeding an administration plan aimed at returning the cia ’s focus to traditional intelligence gathering and possibly bringing more transparency to drone strikes . this marks the largest death toll by a drone strike in yemen , aqap ’s inception . the move also reflects some lawmakers ’ lingering doubts about the u.s. military ’s ability to conduct strikes against al - qaeda and its regional affiliates without hitting the wrong targets and killing civilians .