ROME (AFP) - Italy's interior ministry has banned fans of Serie A outfit Napoli from travelling to away matches all season after violence flared on the opening day of the season during the encounter with Roma.

Interior Minister Roberto Maroni announced on state broadcaster Rai that "members of Napoli fan clubs are banned from travelling for the duration of the season."

Maroni spoke after an official investigation into Sunday's incidents and ahead of a report back due Wednesday by the national body charged with maintaining public order at sporting events.

Five football fans - initial reports said seven - were arrested after the violent clashes.

A train was vandalised as an estimated 1,000 fans, mostly without tickets, boarded a train at Naples bound for Rome where the match was being played.

During the journey fans broke windows and destroyed toilets and seats, causing damage estimated at 500,000 euros.

Four railroad workers and a ticket collector were injured as well as several police officers in Rome.

"It's unacceptable that such incidents occur and in addition we're only on the first day of the championship," Maroni said Monday.

Italian football federation president Giancarlo Abete said Monday there was an urgent need "to eradicate the groups of delinquents who are polluting the world of football."