Answer: The invasion, which took place along a 2,900-mile (2,800-km) front, caught the Soviet leadership entirely off guard and left the Red Army unprepared and partially demobilized. Guderian's tanks, which were part of Bock's southern flank, raced 50 miles (80 kilometers) past the border on the first day of the invasion and arrived in Minsk, 200 miles (320 kilometers) beyond it, on June 27. They converged at Minsk with Hoth's tanks, which had attacked from the north, but Bock's infantry could not follow up quickly enough to complete the encirclement of the Soviet troops in the area; despite 300,000 prisoners taken in the salient, a large portion of the Soviet forces was able to flee to the east.