England fans were involved in “an altercation” with Serbia supporters before their teams’ opening Euro 2024 match in Gelsenkirchen.
Videos on social media showed tables, chairs and bottles thrown in the German city before riot police arrived.
Local police told the BBC that two groups were separated and that seven people from Serbia were arrested, one of whom is the subject of a criminal complaint for grievous bodily harm.
The UK Football Policing Unit (UKFPU) said it is liaising with German authorities and reviewing footage.
Meanwhile, Hamburg police shot and seriously injured a man who they say threatened them on Sunday.
A Hamburg police spokesperson told the BBC the suspect was armed with a pickaxe and had tried to ignite a petrol bomb – but that officers responded with pepper spray and then shot him.