On August 8, Tukhachevsky issued his order for the capture of Warsaw, in which the 16th Army was to attack the city from the east, covered on its flank by the Mozyr Group of Forces. During the Battle of Radzymin between August 13 and 16, the army's 27th Omsk Rifle Division, commanded by Vitovt Putna, fought to capture Radzymin, which changed hands more than five times during the fighting. At the same time, Polish leader Józef Piłsudski's Assault Group began the counteroffensive. They quickly broke through the understrength Mozyr Group on 16th Army's flank, and on 18 August the army came under attack from both the three divisions of the Assault Group's 4th Army on its flank and the 10th and 15th Divisions advancing from Warsaw on its front. Under pressure, the three southernmost divisions of the 16th Army began a precipitate retreat to the east, but then were attacked in turn by troops from the Assault Group. As a result of these actions, the 8th and 10th Rifle Divisions were destroyed, while the 2nd Rifle Division suffered heavy losses. The 17th Rifle Division lost communication with the rest of the army in the chaos, leaving the Putna's 27th as the only intact unit in the army.