Coventry promotion: Video shows men 'chased by group of fans'
Footage shared widely on social media has shown two black men standing behind bins as a group throws bottles and other missiles in Coventry.
The gathering, prompted by Coventry City's promotion to the Championship, had started in a "good natured way" police said, but later saw violence break out.
West Midlands Police said both men were searched, after it was alleged one had brandished a knife, and escorted from the scene.
The force is calling for the public to help "establish the complete circumstances around what happened" and said it would take action if any hate crimes are identified.