Germany longs for the days of invading soccer hooligans.
Police were called to the Altmarkt area of the city over reports of the mass bawl. Officers used CS gas to control the brawling men.
The scores of men were also using telescopic batons in the fight in Druisburg, which is on the west of Germany.
Police said they were spat at and had objects hurled at them.
Around 50 people were arrested and onlookers captured the brutality in shocking photos.
Those arrested refused to explain what sparked the fight and 30 people were later released.
A police official told the newspaper Der Westen: “There are three rival groups. It may be a conflict between Turks, Lebanese and Kurds.
“Unlike with a demonstration of that size, we do not have a contact person, nobody wants to talk to the police.”
He added: “The officers got the situation under control before it escalated.”
HT: Unsavory Agent