These plans, however, were quickly changed, after the Germans destroyed key Polish unit, 21st Mountain Division near the village of Dzikowiec, on September 15/16, killing general Józef Kustroń.
Meanwhile, Operational Group "Boruta" (named after General Mieczysław Boruta-Spiechowicz), which was part of Army Kraków, separated from main Polish forces and marched towards Narol.