Dortmund and Schalke hooligans clashed at the Westfalen Stadium after their Bundesliga match on Saturday.
After the final whistle, which saw the visitors win 4-2, a group of Dortmund hooligans made their way to the away end, where they clashed their Schalke counterparts.
Riot police were called in to quell the trouble.
There were no reports of any arrests.
