Battle of Kursk were mostly behind Army Group North and Army Group Centre. In June 1943, partisans operating in the occupied area behind Army Group Centre destroyed 298 locomotives, 1,222 railway wagons and 44 bridges, and in the Kursk sector there were 1,092 partisan attacks on railways. These attacks delayed the build-up of German supplies and equipment, and required the diversion of German troops to suppress the partisans, delaying their training for the offensive. Central Partisan Headquarters coordinated many of these attacks. In June Soviet Air Forces (VVS) flew over 800 sorties at night to resupply the partisan groups operating behind Army Group
Battle of Kursk of powerful Soviet concentrations behind the Kursk area, Hitler further delayed the offensive to allow for more equipment to reach the front. With pessimism for Citadel increasing with each delay, in June, Alfred Jodl, the Chief of Staff at the OKW, instructed the armed forces propaganda office to portray the upcoming operation as a limited counteroffensive. Due to concerns of an Allied landing in the south of France or in Italy and delays in deliveries of the new tanks, Hitler postponed again, this time to 20 June. Zeitzler was profoundly concerned with the delays, but he still supported the offensive.