north, but failed to reach it by a few kilometers. On 29 June the corps had 32 tanks remaining out of the original 453. 8th Mechanized Corps Ryabyshev's 8th Mechanized Corps finally arrived on the scene on the 25th. On 26 June 1941, the 8th Mechanized Corps as a whole successfully attacked in the direction of Brody–Berestechko against parts of the German 11th Panzer Division. Despite haphazard arrangements and difficulties, the Soviet attack met with some initial success, catching the Germans on the move and outside their prepared positions, their tanks sweeping aside hastily arranged German anti-tank positions manned by motorcycle troops attached to the 48th Panzer Corps. Later the 8th MC split, with some amalgamating into Popel's group and a second force remaining under the command of Ryabyshev. 12th Tank Division Fifty-six KV and 100 T-34 tanks of this division ran out of fuel and ammunition while attacking near Dubno. Combat operations were forced to a standstill. Popel's group Popel's group had about 300 tanks, including no less than 100 T-34 and KV tanks. On 27 June, Popel's group surprised and defeated the rear of 11th Panzer Division and captured Dubno, a road crossing of strategic importance. This was the most successful Soviet action of the battle, as it cut off supply lines of the German armoured spearhead (the 11th Panzer Division). However, this was not exploited by Soviet command, who failed to communicate with Popel and to provide supplies or reinforcements. The group waited in Dubno and prepared for defence, losing the operational initiative. The situation was considered "serious" by the German high command: By 28 June the Germans had gathered enormous forces. The Popel's group came under attack by elements of the 16th Motorized, 75th Infantry Division, two other infantry divisions, and the 16th Panzer Division. Encircled in Dubno, Popel defended until 1 July, when he retreated. Ryabyshev's group Ryabyshev's group had 303 tanks, including 49 T-34 and 46 KV. On 28 June, in an attempt to follow Popel, it met and attacked the German 57th Infantry and 75th Infantry Divisions, as well as elements of 16th Panzer Division. The attack was unsuccessful and the Soviets quickly retreated. On 1 July Ryabyshev reported in Tarnopol with 207 tanks, including 31 T-34 and 43 KV tanks. With no further combat, the 8th MC moved to Koziatyn, where on 7 July 1941 it had 43 tanks – 5 per