Police in Naples are on high alert in anticipation of possible violent clashes surrounding the Champions League match between Serie A side Napoli and Marseille later Wednesday. Over 800 visiting supporters have bought tickets for the Group F fixture, which has caught the attention of authorities in Italy following violence in Marseille two weeks ago when Napoli defeated the struggling French side 2-1. Sporadic clashes in and around the stadium on October 22, when Napoli fans clashed with French police prior to kick-off, led to several arrests and some fans suffering minor injuries. Inside Marseille's Velodrome stadium, Marseille fans unveiled banners aimed at provoking Napoli's hard-line 'ultras' and the violence resumed at half-time with Napoli fans launching rocket flares and ripped-up seats at their rivals. On Thursday, close to 1000 police officers were deployed in Naples as visiting fans, 450 of whom arrived on three chartered flights from Marseille in the afternoon, touched down in the city. Some French fans had already arrived at the San Paolo stadium four hours prior to kick-off, according to the latest reports, however they were met by a heavy police presence and were shepherded to the away fans' end of the ground. Napoli, meanwhile, have called for their fans' best behaviour because their San Paolo ground is currently subject to a suspended 'closed doors' ban, meaning they could be forced to play their next league game at home in the event of violence. Napoli currently sit third in Group F, but on the same points (six) as leaders Arsenal and Borussia Dortmund, who face each other in Germany. It means Rafael Benitez's side, who are considered title challengers in Italy's Serie A this season, can go second in the group in the event of another win over Elie Baup's men, who sit bottom with no points after three games.