Although the ZNDH had a brief role in the subsequent anti-Partisan offensive, Case Black () in mid-1943, its main involvement was on the front in the central NDH. As always, the Partisan resistance displayed frustrating survivability and effectiveness and new events started to influence the fighting in Yugoslavia. The Partisan forces were well aware of the constant threat of air attack posed by the ZNDH's medium bomber force and on 10 August 1943 undertook a devastating night attack by a brigade on Sarajevo's Rajlovac airfield. The three and a half hour assault on the airfield left 10 ZNDH bombers, plus another five Luftwaffe bombers and transports, destroyed, with another 17 aircraft damaged. Although some aircrews returned fire from the machine-gun turrets of their aircraft, Partisan losses were less than 20. Afterwards ZNDH Command complained that the German ordered dispersal of aircraft around the airfield's perimeter, in case of air attack, made the aircraft especially vulnerable to just this type of ground attack.