Lazio have been handed a suspended one-game stadium ban by UEFA following anti-semitic chanting by home fans in a Europa League game against Tottenham Hotspur in November, Italian media reported on Friday.
UEFA was not available for comment but Lazio President Claudio Lotito told Italian radio the suspended ban, which will be enforced if a similar incident takes place, was a warning to his club's fans.
"For the fault of a few people, we all must pay the penalty. But now there is no more joking," he said.
Tottenham have a large contingent of Jewish fans. Lazio supporters, well-known for their right-wing views, also unfurled a "Free Palestine" banner at the game.
Ten Spurs fans were injured when they were attacked in a Rome bar the night before the match.
UEFA has been accused of being too soft on racist incidents, with pundits pointing out that Denmark's Nicklas Bendtner was handed a bigger fine for displaying an advertising logo on his underpants at Euro 2012 than national federations have received for instances of racism.