At the beginning of German invasion of Yugoslavia, the Yugoslav Royal Air Force (YRAF) possessed some 60 Dornier Do 17Ks that equipped the "3 vazduhoplovni puk" (3rd Bomber Regiment). It was composed of two groups: the 63rd Bomber Group stationed at Petrovec airbase near Skopje and the 64th Bomber Group stationed at Mileševo airbase near Priština.