In the early morning, German planes dropped leaflets that urged the Poles to surrender and claimed that most of Poland was already in German hands, and that further resistance was futile. In order to strengthen the morale of his troops, Władysław Raginis and Lieutenant Brykalski swore that they would not leave their post alive and that resistance would continue. Soon after that a German artillery barrage and aerial bombardment started. The Polish artillery was much weaker and was soon forced to retreat towards Białystok. After preparation, the Germans attacked the northern flank of the Polish forces. Two platoons defending several bunkers located to the north of Narew were attacked from three sides by German tanks and infantry. Initially the losses among German infantry were high, but after heavy artillery fire, the commander of the Giełczyn area, First Lieutenant Kiewlicz, was ordered to burn the wooden bridge over Narew and withdraw to Białystok. The remnants of his forces broke through the German encirclement and reached Białystok, where they joined the forces of General Franciszek Kleeberg.