Complex sentence: On the same day, the corps was reported to be fighting in the Liady and Syrokorenye region, west of Smolensk, while retreating to the Gusino crossing, west of the city.
Split into simpler sentences: On the same day, the corps was reported to be fighting in the Liady and Syrokorenye region, west of Smolensk. It was reported to be retreating to the Gusino crossing, west of the city.