Among those arrested are Luca Lucci and Renato Bosetti, leaders of Milan's and Inter's "ultras", respectively.
This is reported by Italian media and international news agencies.
The supporter groups in Milan are suspected of having taken over parts of the sales of football souvenirs, food, parking, and ticket sales outside the clubs' shared arena Giuseppe Meazza stadium, commonly known as San Siro, through threats, extortion, and violence.
According to the police, the groups have ties to the 'Ndrangheta, one of the world's most extensive criminal syndicates.
Over 50 residences were searched during the raid.
This investigation shows the risks of infiltration of organized crime into professional and non-professional football", says Italy's anti-mafia prosecutor Giovanni Melillo at a press conference.
We must stop pretending that we do not see these risks. It would be wrong to say that all "ultras" are criminals, but it is obvious to everyone that a significant part is involved in criminal activity, says Melillo according to the AFP news agency.
Marcello Viola, prosecutor in Milan, emphasizes that Serie A clubs Inter and Milan are among those affected by the criminality, but that they must show that they have broken all ties with criminal elements in the supporter leadership.
