Napoli fans were reportedly involved in conflicts with French Police ahead of their friendly against Nice.
French special units were waiting in place because of Nice supporters’ friendship with the Partenopei’s rivals Inter and the game was classified as being at risk in advance.
According to La Gazzetta dello Sport, a group of Napoli fans threw a paper bomb outside the Allianz Riviera stadium which caused a fire near the motorway that led to firefighters arriving on the scene immediately and the road’s toll gate was closed for an hour.
Armed riot forces then responded with tear gas to disperse the Napoli fans who moved to a corner of the stadium by the Museum of Sport and Police turned away other Italian supporters as they attempted to bring the situation under control.
There were also reports of Azzurri fans throwing rocks down onto the street from an overpass above the motorway.
The French Division Nationale de Lutte contre le Hooliganisme reportedly received information from the Italian interior ministry to expect the arrival of around 300 Napoli fans at risk of causing trouble, although they were difficult to monitor on account of them arriving in cars rather than as a group.
The French authorities also feared the potential presence of Genoa supporters who are twinned with Napoli, after they were involved in an incident against Nice in 2009 in Cuneo, but there are no reports of them being present.
