Rome police have identified 20 Lazio fans who they say littered the Stadio Olimpico with images of Anne Frank -- the young diarist who died in the Holocaust -- wearing the shirt of city rivals Roma.
Police used closed-circuit video footage to try to find the offenders.
Thirteen of the fans are being investigated for acts of racial discrimination "for putting up anti-Semitic material featuring offensive content which could incite racial hatred."
Police also say that 13 of the fans have been banned from attending sports events in Italy -- 12 of them for five years and one for eight years because that person had already served three previous such bans.
Six of the fans belong to the ultras group "Irriducibili," police said.