In late April and early May 1944, the German authorities decided to transfer a significant part of the police duties in Lithuania to the newly created LTDF formation,[2] which was ordered to initiate a wide anti-partisan operation against the Polish and Soviet partisans in the area.

[3][10] Faced with the need to protect Polish civilians, the AK decided to fight back in early May, and organized a concentrated assault against the fortified Lithuanian positions around the village of Murowana Oszmianka.

[11] The assault was a success, partially because other Lithuanian garrisons in nearby towns did not move from their posts;[6] German reinforcements were stopped by sabotage of bridges and delaying actions (carried out primarily by the 9th Brigade).

[12] During the battles in Murowana Oszmianka and Tołminowo, the 301st battalion was practically wiped out;[2] only the 4th company managed to evade Polish forces and retreat.

[2][13] After the battle, all Lithuanian prisoners of war were disarmed (the Polish resistance was able to capture one mortar and seven machine guns) and released with only their long johns and helmets on.

[17] After their defeat in the battle of Murowana Oszmianka and other skirmishes against the Home Army, the LTDF became so weakened that Povilas Plechavičius and his officers were judged to be useless by the Germans and were relieved of command.