Turkish Armed Forces (TAF) had received information about activities in the region on the night of December 28, which was supplied by United States intelligence services[11] based on a U.S. drone flight.[12] The TAF reviewed the footage from unmanned aerial vehicles flying over the terrain, and evaluated the smugglers as a group of militants of the Kurdistan Workers' Party (PKK). Pentagon officials were quoted as saying that American drones initially spotted the group, but after alerting the Turks and offering to conduct more detailed surveillance they were denied and "Turkish officers instead directed the Americans who were remotely piloting the drone to fly it somewhere else."[13] Two F-16 Fighting Falcons of the Turkish Air Force bombed the area.[4][14] This happened after they received the information that evening from the U.S. IAI Heron drone, as stated by a survivor, Servet Encü.[15]