Battle of Kursk guns and mortars. In 1943 an offensive by the Soviet Central, Bryansk and Western Fronts against Army Group Centre was abandoned shortly after it began in early March, when the southern flank of the Central Front was threatened by Army Group South. Soviet intelligence received information about German troop concentrations spotted at Orel and Kharkov, as well as details of an intended German offensive in the Kursk sector through the Lucy spy ring in Switzerland. The Soviets verified the intelligence via their spy in Britain, John Cairncross, at the Government Code and Cypher School at Bletchley Park, who clandestinely forwarded
Battle of Kursk German historian Karl-Heinz Frieser. German historian Roman Töppel disagrees. Having consulted the armies and units archives, he writes that Krivosheyev's figures on Soviet losses at Kursk are underestimated by 40%. Krivosheyev calculated total Soviet losses during the German offensive as 177,877 casualties. The Central Front suffered 15,336 irrecoverable casualties and 18,561 medical casualties, for a total of 33,897 casualties. The Voronezh Front suffered 27,542 irrecoverable casualties and 46,350 medical casualties, for a total of 73,892. The Steppe Front suffered 27,452 irrecoverable casualties and 42,606 medical casualties, for a total of 70,085. During the two Soviet offensives, total casualties amounted to