Police in the Greek city of Thessaloniki fired tear gas late Wednesday to disperse rioting local Iraklis football fans protesting their team's relegation.
The clashes, in which riot police also used stun grenades, closed down the northern port's center to motorists as fans smashed shop windows and bus stops, and set fire to rubbish bins.
Police detained 40 suspected rioters. No injuries were immediately reported.
Police said the violence started when youths tried to set fire to cars during a march by some 1,500 Iraklis fans. Earlier Wednesday, Greek football authorities rejected an appeal by the first-division team against its relegation to the second tier next season over its troubled finances.
Greece has been plagued for years by football violence, despite repeated government pledges to crack down on troublemakers. Saturday's cup final between AEK and Atromitos was marred by extensive rioting and pitch invasions.
