AC Milan players walked off the field because of racist chants, abandoning an exhibition match in the first half with lower division club Pro Patria on Thursday.
The game was interrupted and later ended because of chants directed at several black Milan players, despite appeals to stop from the public address announcer.
After repeated chants directed his way, Ghana midfielder Kevin-Prince Boateng picked up the ball and kicked it at a section of the crowd in the 26th minute of the first half.
Boateng took off his shirt and walked off the field with his Milan teammates. Urby Emanuelson, Sulley Muntari and M'Baye Niang also were targeted by the chants.
"Walking off was the right choice when faced with something like this," Milan coach Massimiliano Allegri said. "We need to stop these uncivil gestures. Italy needs to improve and become better educated and more intelligent."
The match, which was scoreless at the time, was not resumed. The game was played in Busto Arsizio, a town located north of Milan. Pro Patria plays in Italy's fourth-tier division.
Milan said on its website that the insults came from a small group of Pro Patria fans, adding other supporters disassociated themselves from the chants.
Milan, returning from its holiday break, is preparing to play Siena on Sunday.