Turkey, Iran launch coordinated investigation into death of Turkish soldiers at border Turkey's Ministry of Defense announced that Turkish soldier Yusuf Sait Onlu was killed on October 31, 2026 while responding to an alleged illegal border crossing attempt near the Engin Mayın border post along the Turkish border. Iran border. The ministry said that it is likely that the fatal shooting originated on the Iranian side of the border. Turkish authorities immediately launched legal and administrative investigations, while Turkish and Iranian officials met at the site of the incident on November 3. Iranian authorities have also initiated their own investigations, as the two countries continue to coordinate efforts to establish the full circumstances surrounding the soldiers' deaths.