 The northern section of Army Group South faced the Southwestern Front , which had the largest concentration of Soviet forces , and the southern section faced the Southern Front . In addition , the Pripyat Marshes and the Carpathian Mountains posed a serious challenge to the army group 's northern and southern sections respectively . On 22 June , only the northern section of Army Group South attacked , but the terrain impeded their assault , giving the Soviet defenders ample time to react . The German 1st Panzer Group and 6th Army attacked and broke through the Soviet 5th Army . Starting on the night of 23 June , the Soviet 22nd and 15th Mechanized Corps attacked the flanks of the 1st Panzer Group from north and south respectively . Although intended to be concerted , Soviet tank units were sent in piecemeal due to poor coordination . The 22nd Mechanized Corp ran into the 1st Panzer Army 's III Motorized Corps and was decimated , and its commander killed . The 1st Panzer Group bypassed much of the 15th Mechanized Corps , which engaged the German 6th Army 's <unk> Infantry Division , where it was defeated by antitank fire and Luftwaffe attacks . On 26 June , the Soviets launched another counterattack on the 1st Panzer Group from north and south simultaneously with the 9th , 19th and 8th Mechanized Corps , which altogether fielded 1649 tanks , and supported by the remnants of the 15th Mechanized Corps . The battle lasted for four days , ending in the defeat of the Soviet tank units . On 30 June Stavka ordered the remaining forces of the Southwestern Front to withdraw to the Stalin Line , where it would defend the approaches to Kiev . 
