The ugly scenes were broken up by police using tear gas.
Chelsea are set to face Real Betis tonight in the UEFA Conference league final in Wroclaw. The Blues will hope to become the first-ever club to win all three European titles.
Around 70,000 fans were expected to arrive into the city for the final.
Footage has now emerged on social media of a brawl between fans of the English and Spanish sides on Tuesday.
The incident took place between Chelsea and Betis fans at the Kombinat pub and the Guinness pub across the road in Solny Square. Both fans can be seen hurling chairs and other missiles at one another.
Polish police reacted immediately to the situation. They kept the opposing fans at bay with tear gas sprayed in the direction of Blues supporters.
The Provincial Police Headquarters in Wroclaw released a statement. They claimed there was no further escalation of the conflict or negative behaviour after officers reported to the scene.
The local police force said: “The fans scattered in different directions and currently the police officers of the criminal division are conducting activities aimed at identifying them.”
Footage from after the sun had gone down shows the square still engulfed in the chaos from the fans.
