Milan, January 3 - Italian soccer was outraged Thursday when AC Milan's friendly at fourth-tier side Pro Patria was abandoned after the Serie A giants' black players were the target of racist chants from home fans. The match at Busto Arsizio north of Milan was first interrupted and then scrapped altogether after Milan captain Massimo Ambrosini led his teammates off the pitch. Milan midfielder Kevin Prince Boateng kicked the ball towards fans who were directing abuse at him before the action stopped. M'Baye Niang, Urby Emanuelson and Sulley Muntari were also targeted. Italian football has been battling racism in the stands for a number of years after several shameful high-profile incidents. The head of the Italian soccer federation (FIGC), Giancarlo Abete, voiced solidarity with the players and club, calling the incident "an indecent ruckus that offends the whole of the soccer world". He also said FIGC prosecutors would be looking into the case. In a statement, FIGC said: "No sanction or penalty can erase the disdain for an unjustifiable and intolerable episode". "We need to react with strength and without silence to isolate the few delinquents that transformed a friendly match into a mess that offends all of Italian football," it said. Italian players' association president Damiano Tommasi applauded Milan's decision to walk off. "It was a good signal, even if a sporting event should never be placed in doubt by acts like these," said the former AS Roma and Italy midfielder. "Pulling out was the right decision when faced with something like this," said Milan coach Massimiliano Allegri. "These uncivilised gestures must stop. Italy must improve and become more educated and more intelligent". "We promise to return (to replay the game), and we are sorry for the club and players of Pro Patria, but we could not make any other decision. I'm sorry for the families and children who had come here to enjoy a beautiful day. I hope this can be an important signal." Ambrosini said: "We were annoyed from the beginning. We wanted to give a strong signal...we could not continue the game in an atmosphere like this." Boateng tweeted "It's a disgrace that things like this are still happening while star striker Stephan El Shaarawy, also on Twitter, said: "I'm really speechless, it was a shameful afternoon. I'm sorry for the intelligent people present at Busto but it was right to leave". Barbara Berlusconi, daughter of owner Silvio Berlusconi and a club director, said: "You need zero tolerance for episodes like this. "Matches must be stopped straight away, even in the (Serie A) championship...You can't always pretend not to see or hear". Pro Patria said the chanters were a "stupid bunch of three or four", adding it might try to take legal action against them. Milan, returning from its holiday break, is preparing to play Siena on Sunday. Meanwhile police from nearby Varese, the provincial capital, said all the offending fans had been identified. Racism has been a problem in Italian soccer at least since the 1980s, when Milan's Dutch star Ruud Gullit spoke out against it. Messina's Ivory Coast defender Zoro threatened to halt a Serie A game in Italy in November 2005 after suffering racial abuse from visiting Inter Milan supporters. A decade earlier, Aaron Winter, a native of Suriname of Hindustani extraction, was subject to attacks at Lazio involving cries of 'Niggers and Jews Out'. The popularity of Italy striker Mario Balotelli spurred hopes racism could be stamped out, at least in the domestic league. Former Inter Milan forward Balotelli, now at Manchester City, has repeatedly been subjected to racist taunts playing for club or country outside Italy. Anti-Semitism has also been a recurring problem in the top flight. In 1989 Israel striker Ronnie Rosenthal, was unable to play even one game for Udinese because of massive pressure from neo-Fascist circles. Lazio supporters, who include a neo-Fascist hard core, were linked to a brutal assault on Tottenham supporters, a London club with a Jewish heritage, in a Rome pub in November.