PESHAWAR, Pakistan — The bullet-riddled bodies of three men were found Sunday by a road in Pakistan's restive northwestern tribal region, killed by suspected Pakistani Taliban militants in apparent retaliation for recent US drone strikes in the area, officials and a villager said.The corpses were discovered in North Waziristan alongside the Miran Shah-Data Khel road that leads to Afghanistan. A note under a rock next to the bodies said "Anyone who dares spy for the Americans will meet the same fate," according to two intelligence officials who spoke on condition of anonymity because they were not authorized to speak to the media.RELATED:Video: Recreation of Times Square bomb, 'Devastating'Afghanistan: NATO says 9 troops killed in helicopter crashLocal government official Asghar Khan confirmed the report, but refused to give further details or release the identities or nationalities of the victims.The slayings came the day after two suspected US missile attacks killed 16 people in the region, part of a recent surge in drone strikes in Pakistan along with stepped-up NATO operations along the frontier. The strikes have been targeting Taliban and al-Qaida militants taking shelter across the porous border in Pakistan out of reach of US ground forces in Afghanistan.Akhtar Nawaz, a local villager, said he did not know who the three slain men were, but that people in the area were convinced they were killed by Taliban militants in response to the American attacks."This is because of the high number of drone strikes these days," he said. Though Pakistan has been highly critical of the drone strikes, Saturday's attacks indicated the U.S. has no intention of sidelining a tactic it considers highly successful despite increased tensions between Washington and Islamabad.Pakistan shut down the Torkham border crossing — the most important NATO supply route into Afghanistan — on Thursday in apparent protest of a NATO helicopter attack that killed three Pakistani soldiers on the frontier. It was the third such incursion into Pakistan in less than a week.While the Pakistani leadership has quietly accepted drone strikes over the last three years and even provides intelligence for some of them, closing the border crossing was a clear signal it will not compromise on allowing foreign troops or manned aircraft inside its territory.