“Based on an assessment we made at the end of May, we believe there is a very high chance German and Polish trouble-makers will start fights,” Oliver Malchow, chairman of the German Police Union (GdP) told The Local.
“We are talking about a ‘traditional hostility’ that goes back years between violent football fans on either side.”
Germany play Poland on Thursday evening in a match that could end up deciding who wins Group C of the European Championships after both sides won their opening matches.
The last time the teams met in the Euros, in Austria in 2008, hooligans fought out one of largest street battles in the history of the competition, the Rheinische Post reports.
Whereas on that occasion German police were able to offer ground support to their Austrian colleagues, this time they can only attend as advisers because police are only allowed to be deployed in another EU country if they speak the local language.
Past games between Poland and Germany which had been categorized as “high risk” had almost always ended up in violence, much of which was directed against police officers, Malchow pointed out.
He claimed though that there was “trust” on their part in their French colleagues “to deal with these presumed disturbances independently and professionally.”
So far German police have arrested over 20 known hooligans who were attempting to travel to France and seized face masks and balaclavas from them.
Lille hooligans ‘identified’
After around 50 German hooligans attacked Ukrainian football fans before their Euro 2016 match on Sunday, police say they have identified some culprits.
The Rheinische Post reports that at least 200 fans with records of violence were present in Lille.
“Officers familiar with the [hooligan] scene could identify a few people from the photos,” a police spokesperson told Bild.
Several Ukraine fans were lightly injured after German hooligans attacked a street in which they were sitting at street cafes.
The hooligans threw bottles and chairs as well as shouting right-wing slogans. Some also published pictures of themselves on social media holding a Reichskriegsflagge (war flag of the Reich) - a symbol associated with far-right groups.
The extent of hooligan violence at Euro 2016 thus far has caught French authorities on the back foot, with English and Russian fans fighting brutal battles in the streets of Marseilles in the build up to their match on Saturday.
UEFA are now threatening to throw Russia out of the competition after their fans attacked England supporters in the stadium after the match.