Wagner is believed to have a Serb unit, which was, until at least April 2016, under the command of Davor Savičić, a Bosnian Serb who was a member of the Serb Volunteer Guard (also known as "Arkan's Tigers") during the Bosnian War and the Special Operations Unit (JSO) during the Kosovo War. His call sign in Bosnia was "Elvis". Savičić was reportedly only three days in the Luhansk region when a BTR armored personnel carrier fired at his checkpoint, leaving him shell-shocked. After this, he left to be treated. He was also reported to had been involved in the first offensive to capture Palmyra from the Islamic State (ISIL) in early 2016. One member of the Serbian unit was killed in Syria in June 2017, while the SBU issued arrest warrants in December 2017, for six Serbian PMCs that belonged to Wagner and fought in Ukraine, including Savičić. In early February 2018, the SBU reported that one Serb member of Wagner, who was a veteran of the conflict in Syria, had been killed while fighting in eastern Ukraine.