|Tear gas fired into the crowd during a Serie A match last year [GALLO/GETTY]
The Naples-based Camorra crime syndicate may be contributing to football violence in Italy, Interior Minister Roberto Maroni said.
The opening weekend of the Serie A season earlier this month was marred when Napoli fans caused a riot on a train to Rome.
A group of several hundred Napoli supporters launched firecrackers, broke windows, slashed seats open and caused $730,000 worth of damage to the train.
At least four railway workers were injured.
More violence erupted when the train reached the capital for the AS Roma-Napoli game, which ended 1-1.
Maroni said that of the 3,096 Napoli fans who purchased a ticket for the Roma game, 27 of them had links to the Camorra.
"The presence of such a large number of people accustomed to criminal conduct, in particular those belonging to or linked to Camorra clans, constitutes an extra risk factor for more violence at football matches," Maroni said.
Earlier this week a sports judge ordered parts of San Paolo stadium in Naples
closed until next month, shutting down where hardcore Napoli fans usually sit.
Napoli fans have also been barred from away games for the rest of the season.
Also, Maroni announced that the government would start a commercial campaign against soccer violence, broadcasting spots on TV and on stadium jumbo screens and posting ads on team web sites.
Catania fans banned
Further developments saw Catania supporters banned from attending Saturday's Serie A game at Inter Milan.
Bans on fans attending certain matches were used regularly in Italy last season following the deaths of a policeman and a supporter of Rome club Lazio in separate incidents in 2007.
But Maroni has signalled his intention to adopt an even harder line this time.
"From now on, if a match is considered high risk, away fans will automatically be banned and if it's considered very high risk I'll consider having it played behind closed doors," Maroni told a Senate commission on Wednesday.
"There will be no tolerance of violence," he added as he announced that he was stopping Catania fans from travelling after Italy's soccer security body (CASMS) had previously given them the green light.
CASMS had already banned Fiorentina and AC Milan fans from their respective Sunday games at Napoli and Genoa, considering them high-risk encounters.
Maroni said clubs whose fans caused serious disturbances risked having them banned from away games all season, like Napoli's.