from Pińsk. He did not believe the city could or should be defended any longer and ordered some troops to retreat into the region of Sopoćkiń and Kalet to cover forces moving into Lithuania. The same day, the leader of the command of District Corps left the city, without appointing any officer responsible for further defense. District head Walicki and president of the city Cieński also moved out. Another wave of communistic supporters came out; this time they took over the square of Batory in the city centre. The 31st guard battalion had its alert platoon in action, resulting in elimination of the threat. Poles mounted machine guns on the towers of nearby churches of the city. Comparison of Forces Polish General Wacław Przeździecki's Grodno Defense Group included Edmund Heldut-Tarnasiewicz's Wołkowysk Cavalry Brigade, Stanisław Szostak's 32nd Armored Reconnaissance Group, and the 94th Artillery Battery. Soviet Komkor Ivan Boldin's Dzerzhinsky Cavalry-Mechanized Group included the 6th Cavalry Corps (4th, 6th, and 11th Cavalry Divisions), the 5th Rifle Corps (4th and 13th Rifle Divisions), and the 15th Tank Corps. The 15th Tank Corps, commanded by Mikhail Petrov, included Kombrig Alexey Kurkin's 2nd Tank Brigade, Colonel Ivan Yushchuk's 27th Tank Brigade, and Colonel Berdnikov's 20th Motor Rifle and Machine Gun Brigade. The Soviet troops also included the 21st Tank Brigade. Battle Ill-equipped, undermanned and lacking any anti-tank artillery, the Polish defenders relied mostly on improvised anti-tank means such as bottles of gasoline or turpentine, small arms fire, and anti-tank obstacles. On 20 September, the tanks of the Soviet 27th Light Tank Brigade of the 15th Tank Corps reached the city's outskirts. Although both numerically and technically superior, the Soviet forces lacked infantry support and oil, which stopped many tanks. Also, the tank crews had no experience in urban warfare, which was a significant help for the defenders. The Soviets tried to seize the city from the south through the bridge over the Niemen River. However, the initial assault was repelled. In the early morning of 21 September, the defenders were joined by the remnants of the reserve Wołkowysk Cavalry Brigade under Brigadier General Wacław Przeździecki. After two days of heavy fighting, often in close quarters, much of the city centre was destroyed by Soviet artillery. Seeing no chance for further defence, on 22 September the remainder of the Polish forces withdrew towards the Lithuanian border. According to Soviet sources, the Red Army suffered casualties