Italian police have opened an investigation after Lazio football fans posted stickers of Holocaust victim Anne Frank wearing the jersey of rivals Roma alongside anti-Semitic slogans.
The material was found in an area of Rome's Olympic Stadium occupied by hard-core Lazio fans known as "ultras".
Italian President Sergio Mattarella called the case "alarming".
Anne Frank became famous for her diary of life as a German Jew in Nazi-occupied Amsterdam in World War Two.
Local rivals Lazio and Roma share the stadium, and the "ultras" - known for their racist chants and often violent behaviour - left the stickers and anti-Semitic slogans such as "Roma fans are Jews" during a match on Sunday.
The head of Rome's Jewish community, Ruth Dureghello, posted a picture of the stickers on Twitter, and added: "This is not soccer, this is not sport. Anti-Semites out of the stadiums."
Questa non è una curva, questo non è calcio, questo non è sport. Fuori gli antisemiti dagli stadi. pic.twitter.com/Q1uJnDQ7Cl— Ruth Dureghello (@dureghello) October 23, 2017
The post was then retweeted by Rome's Mayor Virginia Raggi, and the Italian football association is expected to investigate the case.
Sports Minister Luca Lotti said that those responsible would be "identified and punished", adding: "There is no justification. These are instances to be condemned unconditionally."
Lazio president Claudio Lotito visited a synagogue in Rome and brought a floral wreath to remember Holocaust victims.
"I am here to express our total dissociation towards all xenophobia, racism, anti-Semitism," he was quoted by Italian newspaper La Repubblica (in Italian) as saying.
He added that the club would take 200 fans every year to visit the museum on the site of Nazi death camp at Auschwitz, where more than one million people were murdered.
Italy's football federation said in a statement that a minute's silence will be held and a passage read from Anne Frank's famous diary before this week's games.