Polish armies attempted to attack, launching the Battle of the Bzura, one of the largest of WWII. Although the enemy was inflicted considerable losses, the battle ended in defeat. Defensive fighting would have certainly lasted longer, if not for the invasion of the Red Army on September 17. Оборонительные бои, несомненно, могли бы продолжаться и дальше, если бы не нападение Красной армии 17 сентября.
