Flota Swinoujscie and Gwardia Koszalin fans clashed during their Polish fifth division match on Sunday.
The incident occurred in the second half of the match, shortly after Flota Swinoujscie had taken a 3-0 lead.
A group of Gwardia Koszalin fans charged across the pitch and attacked their Flota Swinoujscie counterparts on the opposite side.