Complex sentence: The cavalry was followed by several large wagons filled with reinforcements of police, at this site the mov once again turned around and retreated to the other side of the bridge while being fired upon by the police and beat by their clubs.
Split into simpler sentences: The cavalry was followed by several large wagons filled with reinforcements of police. At this site, the mob once again turned around and retreated to the other side of the bridge while being fired upon by the police and beaten by their clubs.