Heracles Almelo and Ajax fans were involved in a brawl during their Eredivisie match at the Polman Stadium on Saturday night.
The melee broke out midway through the second half after a group of Ajax fans, standing in a section occupied by Heracles fans, reportedly stole a flag from their rivals.
There were also Cracovia fans among the Ajax fans.
Police and stewards were forced to intervene to separate the warring fans.
