Complex sentence: Fighting died down and was sporadic throughout the hours of darkness; after the brutality of the day's combat, both sides avoided contact although frequent Polish artillery strikes continued to harass German forces retreating from the sector.
Split into simpler sentences: Fighting died down and was sporadic throughout the hours of darkness; after the brutality of the day's combat, both sides avoided contact. However, frequent Polish artillery strikes continued to harass German forces retreating from the sector.