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 by the British intelligence service and Tunny intercepts. Aware months in advance that the attack would fall on the neck of the Kursk salient, the Soviets built a defence in depth designed to wear down the German armoured spearhead. The Germans delayed the offensive while they tried to build up their forces and waited for new weapons, mainly the new Panther tank but also larger numbers of the Tiger heavy tank. This gave the Red Army time to construct a series of deep defensive belts. The defensive preparations included minefields, fortifications, artillery fire zones and anti-tank strong points, which extended