The Italian police have arrested four people after a mass brawl at a motorway service area between hooligans from AS Roma and SSC Napoli.
These are three supporters of the Roma and one from Naples.
The A1 motorway was temporarily closed on Sunday due to the riots near the Tuscan city of Arezzo, resulting in a 15-kilometer traffic jam.
According to the police, around 300 people were involved in the riots, 180 have already been identified.
The hooded Tifosi are said to have thrown smoke bombs and firecrackers at each other.
A Rome fan who was stabbed and required hospital treatment has been arrested.
Leaders Napoli played at Sampdoria Genoa on Sunday, Roma at AC Milan.
The traffic chaos extended the journey of many holidaymakers who were on their way home after the Christmas holidays.
Italian Interior Minister Matteo Piantedosi plans to meet with FIGC Football Federation boss Gabriele Gravina on Wednesday to discuss preventive measures.
The police had recently warned that clashes between rival fan groups would increasingly take place away from the heavily monitored stadiums.