Italian prosecutors will press charges against at least one person after racist abuse during a soccer game prompted AC Milan players to walk off the field in the middle of a game.

Police and stadium cameras have identified a 20-year-old man and prosecutors expect to identify more people to charges, prosecutor Mirko Monti told CNN.

AC Milan's Kevin-Prince Boateng, the main target of the abuse, kicked a ball into the stands, tore his shirt and led his team off the field Thursday in a rare protest against racist behavior by soccer fans.

Boateng was one of several black Milan players, along with M'Baye Niang, Urby Emanuelson and Sulley Muntari, who were the targets of racist abuse in the friendly against Pro Patria.

Boateng, who was visibly upset by the chanting, picked up the ball and kicked it into the crowd. After the incident, Boateng tweeted: "Shame that these things still happen... #StopRacismforever."

"We are disappointed and saddened by what has happened," Milan coach Massimiliano Allegri told reporters.

"Milan play for the right to respect all players. We need to stop these uncivilized gestures.

"We are sorry for all the other fans who came here for a beautiful day of sport.

"We promise to return, and we are sorry for the club and players of Pro Patria, but we could not make any other decision.

"I hope it can be an important signal."

Italian Football Association president Giancarlo Abete also hit out at the unsavory scenes and announced an investigation into the incident.

Abete said in a statement on the Italian FA website: "No sanction or measure can erase the disdain for an unspeakable and intolerable episode.

"We must react with force and without silence to isolate the few criminals that transformed a friendly match into an uproar that offends all of Italian football."

Boateng is not the first footballer to take a stand over racist abuse.

Former Barcelona striker Samuel Eto'o threatened to leave the field back in February 2006 after being subjected to racist abuse and pelted with bottles during a game against Real Zaragoza.

The Cameroon forward, who now plays for Anzhi Makhachkala, tried to walk off only to be persuaded to remain by then manager Frank Rijkaard.

And in 2011, Brazilian defender Roberto Carlos walked off the field after a banana was thrown at him during a Russian league game.

Carlos, who was 38 at the time, was playing for Anzhi in the city of Samara in the Caucasus region. The Brazilian is now Anzhi's team director.

After picking up the banana, Carlos walked off the field visibly upset before sitting on the bench.

This season matches across Europe have been punctuated by repeated outbursts of racism. Ahead of the European Championship finals in Poland and Ukraine, UEFA president Michel Platini had urged players to allow the referee to deal with the problem of racist abuse, and stressed that officials could stop games if necessary.