Complex sentence: The first column set off from Valjevo and penetrated the village of Divci and then on 6 December 1941 broke out towards the village of Struganik forcing a group of Serbian civilians to march in front of them as human shields.
Split into simpler sentences: The first column set off from Valjevo and penetrated the village of Divci. Then on 6 December 1941, it broke out towards the village of Struganik, forcing a group of Serbian civilians to march in front of them as human shields.