sentences:  The other factor was the weakening of the Partisans, which was mainly caused by the impact of the "left errors".During this period, Stanišić's Chetniks fought the Partisans in the Nikšić area alongside the Italians, and Đurišić's Chetniks did likewise in the Kolašin district of northern Montenegro.In May, Đurišić's Chetniks defeated the Durmitor Partisan Detachment, which was the last large Partisan unit remaining in Montenegro.