Inter Milan have been fined and warned about their supporters' future conduct after racist chanting was heard during the derby with city rivals AC Milan, the Italian top flight said on Tuesday.
Serie A said Inter would have to pay 50,000 ($66,000) for its fans' repeated "expressions of racial discrimination to a player of the opposing team" and the unfurling of insulting banners, despite multiple warnings by stadium officials.
The fine was also for the use of a laser pen against a player.
The league at the same time slapped AC Milan with a 10,000-euro after its fans displayed offensive slogans during Sunday's match, which ended 1-1. Both clubs were told to work more closely with police and other authorities to stamp out the problem.
No specific mention was made in the league's bulletin that the taunts were directed at Milan forward Mario Balotelli, who was making his first appearance in a derby at the San Siro since he left Inter for Manchester City.
Some hardcore Inter fans were seen waving inflatable bananas during the game while monkey noises were also heard, although they were drowned out by whistles.
It was not clear whether the gestures and chanting were directed at Balotelli or Milan's other black players Sulley Muntari, Kevin Prince Boateng and Cristian Zapata.
But Balotelli -- who had been praised for not reacting to the taunts -- was hit with a 10,000-euro fine for making an "insulting gesture" towards fans at the end of the contest.
Italy has been in the spotlight for its handling of racist incidents at football matches since Prince-Boateng stormed off the pitch in a friendly between Milan and lower-league side Pro Patria in January following abuse from some fans.
The match was abandoned and Boateng won plaudits worldwide for his stand.