guns. An auxiliary strike against Kupiansk was to be executed by the Special Group of Vladimir Selivachyov composed of the 8th Army, 3rd and 42nd Infantry Division of the 13th Army – 49,700 bayonets, 3,900-4,200 sabers, 268 guns, and 1,381 machine guns. The total length of the front of the offensive was . The 14th Army was to support the offensive of Selivachev's group, by attacking Lozovaya. The beginning of the counter-offensive of the Red Army was scheduled for 2–5 August, but by that time the preparation was not completed because of the slow transfer of reinforcements, reserves, weapons, ammunition and food supplies to the Southern Front. The planned grouping of troops did not provide sufficient forces and means yet to launch the attack. The White Command became aware of the impending counteroffensive and preventive measures were taken. On 10 August, the White Guard 4th Don Cavalry Corps, under Konstantin Mamontov, broke through the Red front at the junction of the 8th and 9th Armies, and started operating in the rear of the Southern Front around Tambov. The actions of Mamontov's cavalry made it very difficult for the Red Army to prepare and execute the counter-offensive. Progress of the operations Actions of the Shorin group On 14 August, the troops of the Shorin group, with the support of the Volga detachment of the Volga-Kama flotilla—16 boats, five cannodoks, one floating battery—launched an offensive against the Don Army and the Caucasian Army, which numbered 12,300 bayonets, 21,900 sabers, 93 guns, and 249 machine guns. The troops of the 10th Army in cooperation with the Cavalry corps of Budyonny conducted an offensive against Kamyshin and Tsaritsyn, while the 9th Army attacked Ust-Khopyorskaya. By the end of August, the Cavalry corps of Budyonny had defeated General Sutulov's Cossack Division and together with the 10th Army struck a blow against the White troops in the village of Serebryakovo-Zelenovskaya, capturing four armored trains. In early September, heavy fighting for Tsaritsyn unfolded. On 5–8 September, the troops of the 10th Army and units of the Cavalry Corps of the Budenny continued to attack. Under strong White fire, they stormed several times the trenches and wire fences, but due to heavy losses were forced to stop the offensive. On 9 September, White troops launched an offensive by large infantry and cavalry forces with the support of 12 batteries, armored cars and tanks against the 10th Army, and