Battle of Szack Battle of Szack ( Shatsk ) was one of the major battles between the Polish Army and the Red Army fought in 1939 in the beginning of the Second World War . Eve of the Battle . During the invasion of Poland the Polish Border Defence Corps ( " KOP " ) was severely stripped of all the reserves and heavy armament . All the available Polish forces were sent to the west to reinforce the units resisting the German invasion . When the Red Army invaded Poland on September 17 , there were barely any Polish forces to oppose them . The garrisons of the KOP were overstretched and after initial clashes and skirmishes for the border forts , the Polish units had to fall back . The deputy commander of the KOP , general Wilhelm Orlik - Rueckemann decided to unite as many troops under his command as possible and join with the rest of Polish forces in the west . He ordered all the KOP forces in Polesie area to withdraw . In several days he managed to gather approximately 9 000 men under his command , coming from various units spread along a 300 kilometre long strip of the Polish - Soviet border . On September 19 he ordered all his units to march towards Kowel , where his forces were to be joined by the Independent Operational Group Polesie under general Franciszek Kleeberg . However , the difficult situation and the outcome of the battles of Brześć and Kobryń forced Rueckemann ' s group to change the plans . The Polish units changed the direction and started to march through the forests towards Włodawa and Kamień Koszyrski . The group found itself in a no - man ' s - land between the Soviet forces and the Wehrmacht and could operate freely . However , the morale of the troops was low and on September 27 general Orlik - Rueckemann decided to engage the Soviet forces in order to achieve a victory and raise the morale . Battle . The Polish forces were marching in two columns . In the early morning of September 28 the northern column reached the forests near the village of Mielniki while the southern column reached the forests east of Szack ( now Shatsk ) . Polish reconnaissance reported that the town of Shatsk was occupied by Soviet infantry and tanks . Orlik - Rueckemann ordered both columns to form a defensive line along the border of the forest and provoked the Red Army to attack . At 8 o ' clock in the morning the Soviet tank unit ( composed mostly of the T - 26 tanks ) started a direct assault on Polish positions . The Polish forces did not open fire until the tanks came close . When the tanks were only some 500 metres from the Polish lines the Polish Bofors wz . 36 anti - tank guns opened fire . Soon they were joined by the infantry and the 75 mm artillery . All Soviet tanks were destroyed and the battalion of major Balcerzak was ordered to attack the town of Shatsk . The Soviet units were taken by surprise and after a short hand - to - hand fight the Soviet forces were routed . Only a small part of the motorised infantry managed to retreat , but had to leave behind all their lorries , artillery and 9 T - 26 tanks . The Poles also captured the staff headquarters . According to the orders of the Soviet 52nd Rifle Division found in the headquarters , the Soviet units operating from the Kobryń area and were to " clean up the area east of Bug River from the bands of Polish officers " . At 2 o ' clock in the evening the Soviet reserve units appeared in the area and Orlik - Rueckemann decided to withdraw his troops to the forests . After the battle . The Polish forces withdrew unopposed and started their march towards the Bug River . The only Polish unit destroyed by the Red Army was the tabor of KOP " Polesie " Brigade , caught by surprise near the village of Mielnik by the armoured troops of the Soviet 4th Army under general Vassili Chuikov . After a short fight the Polish unit surrendered . Upon the surrender all Polish officers and NCO s were shot on the spot ( about 500 ) . However , the rest of the Polish forces evaded being captured and crossed the Bug River , where they took part in the Battle of Wytyczno .