Inter Milan fans clashed with police officers Sunday as they tried to access Parma's Tardini stadium, from which they had been banned for security reasons, ANSA reported.
About 1,000 Inter fans appear to have entered the stadium despite the ban, while some others remained outside, the dpa reported.
Serie A leaders Inter can secure a third straight title in the season's last game as they visit relegation-threatened Parma.
Inter have a one-point lead on Roma, whose fans were not allowed to attend the game against hosting Catania, who also look to escape relegation.
A bus taking Roma's players to the stadium was hit by a heavy object damaging one of its windows.