Rome (AFP) – Neo-fascists believed to be hardcore fans of Serie A side Lazio held a far-right flash mob ahead of Wednesday’s Coppa Italia semi-final second leg against AC Milan, according to media reports.

Their faces masked by a long banner reading “Honour to Benito Mussolini”, the group sang fascist songs and performed the Nazi salute near the city’s Piazza Loreto, where the defeated dictator’s body was strung up in 1945, the Gazzetta dello Sport newspaper reported.

A short video circulating on social media shows the group holding up the banner, signed ‘IRR’ in a reference to the Irriducibili — Lazio’s hardcore ‘ultra’ supporters who have a long history of hard-right politics.

The flash mob came a day before Italy’s Liberation Day, celebrating the end of Nazi occupation, and ahead of a match in Milan already marked by tension between the two teams.

The Serie A clash between them at the San Siro earlier this month finished with Milan 1-0 winners and scuffles on the pitch after the home players held up the shirt of Lazio player Francesco Acerbi to their own fans like a trophy.

Milan midfielders Tiemoue Bakayoko and Franck Kessie were fined a total of 86,000 euros ($97,000) for the incident.

Meanwhile, a video of racist chants directed at Frenchman Bakapyoko by a group of Lazio fans also circulated on social media.

Milan’s mayor Giuseppe Sala said the police were investigating Wednesday’s flash mob and insisted the northern Italian metropolis “is and will remain forever a profoundly anti-fascist city”.

Italy’s interior minister Matteo Salvini condemned the incident. 

“No tolerance for any form of violence, physical or verbal. I thank the police who are following the incident carefully. Football must be an occasion of celebration and communion, not for fighting or confrontation,” Salvini, an open AC Milan fan said on Twitter.

In Italy “apology for fascism” is a crime, but some cases have been thrown out in recent years on freedom of speech grounds.

February’s first leg of the semi-final between the two sides at the Stadio Olimpico finished goalless.