As the German Sixth Army was encircled in Stalingrad, the Red Army undertook a series of wider attacks against the rest of Army Group South. These culminated on 2 January 1943 when the Red Army launched Operation Star and Operation Gallop, which between January and early February broke German defenses and led to the Soviet recapture of Kharkov, Belgorod, Kursk, as well as Voroshilovgrad and Izium. The Soviet victories caused participating Soviet units to over-extend themselves, though this was largely due to Manstein's strategy of controlled retreat towards the Dneiper.[citation needed] Freed on 2 February by the surrender of the German Sixth Army, the Red Army's Central Front turned its attention west and on 25 February expanded its offensive against both Army Group South and Army Group Center.