Olympique Marseille and Paris St Germain supporters clashed on Sunday after their Ligue 1 game was postponed and the whole PSG team quarantined when three players were diagnosed with H1N1 flu.
Police officers said several people had been injured and one person would undergo leg surgery after being hit by a car. There was no serious damage.
"Police arrested a dozen fans who will appear before a court as quickly as possible," local police chief Philippe Klayman told reporters.
"Small groups of fans wanted to fight each others and we had to react quickly. The French League could have made that decision yesterday so that many PSG fans would have stayed home. We were presented with a fait accompli."
The police had been deployed in numbers because the match, which was scheduled for 2000GMT at the Stade Velodrome, was regarded as a high-risk game.
Police sources said clashes also erupted at the main rail station where PSG supporters were boarding trains to go back to Paris.
Klayman said PSG fans travelling back by bus ransacked motorway services in Peypin, north of Marseille. Three people were detained.
RISK OF CONTAGION
Paris St Germain said their three contaminated players were former France winger Ludovic Giuly, defender and France Under-23 captain Mamadou Sakho and midfielder Jeremy Clement.
The decision was taken "on the formal recommendation of the (national) commission of medical experts", the French Professional League (LFP) said on its website (www.lfp.fr).
The national commission also decided that all PSG players and staff members would be quarantined for the next 72 hours to stop all risk of contagion.
Marseille asked for the game to be played on Wednesday but PSG replied it would not be possible.
"The only available date afterwards would be on Dec. 2 but it is not possible as we also play important games in the Champions League and it would make too many games in a short period of time," Marseille coach Didier Deschamps told reporters.
"In January, four players of ours will play in the Africa Cup of Nations and in February, it would be too late. Playing on Wednesday is a matter of sporting fairness,"
PSG chairman Robin Leproux replied: "Paris will definitely not play on Wednesday."
He said the players would fly from Marseille to Paris later on Sunday and would stay at home for the next three days.
Marseille are fifth on 17 points in Ligue 1 while Paris are 13th on 13 points.
Auxerre climbed to seventh, behind Marseille on goal difference, with a 3-2 victory at home against Lille on Sunday.
Toulouse moved up to 11th thanks to a 2-0 win at second from bottom Lens, who have not won in the league in their last seven games.
Bordeaux lead the table on 22 points after their easy 3-0 win at home against Le Mans on Saturday. Former leaders Olympique Lyon slumped 4-1 at strugglers Nice and stayed on 20 points.
Monaco are second, one point off the pace, after Ligue 1 top scorer Nene netted twice to help them to a 3-1 win at Boulogne.
