Tunisian police fought running battles with football fans protesting their club's exclusion from the national league.
About 150 people, mostly male youth, burned tyres and hurled stones at security forces who responded with tear gas.
The clashes, in the eastern port city of Chebba, lasted until the wee hours of Wednesday morning.
On Monday, the Court of Arbitration for Sport upheld a decision by the Tunisia Football Federation to suspend Chebba Sports Club for non-compliance.
In mid-October, Chebba was banned from competing in the country's premier division for defaulting on the previous season's fines.
The club’s fans allege that their team was unfairly sanctioned for opposing Wadie Jary, the head of Tunisian football who wants to become CAF president.
Chebba Sports Club head, Taoufik Mkacher, in open conflict with the president of the FA, was summoned Wednesday by the National Disciplinary Committee.
In November, some of the club's fans threatened to immigrate to Italy - in protest before reversing their decision.
Tunisia's new football season kicks off on Saturday.