Italian police arrested 19 people accused of criminal ties with the powerful 'Ndrangheta mafia group in a move that decimated the fan clubs backing Serie A teams Inter Milan and AC Milan.

Hardcore supporters of AC Milan and Inter Milan were arrested on Monday for alleged organised crime offences as part of a probe into illegal profits made around matches and the infiltration of mafia gangs into so-called "ultras" groups.

Some 19 people were arrested overall, and variously charged for allegedly being involved in organized crime offenses, including extortion and assault "aggravated by mafia methods," Milan prosecutors said. Three people were put under house arrest, while the others were brought to jail.