Polish units under Apolinary Kurowski numbering around 2500 troops attacked the town in an attempt to gain control of the so-called border triangle - an area at the cross roads of the Austrian, Prussian and Russian partitions which would have allowed the insurgents access to supplies and troops from outside the Congress Poland where the uprising proper was taking place. They were hoping to surprise Russian troops. However, Russian garrison (2 companies, 550 men) was stronger than expected by insurgents. Either the Russian commander guessed the intent, or the strategic plan of the Poles was somehow betrayed. As a result they bolstered their defenses.