Barcelona was fined 1,500 euros ($1,660) and warned by the Spanish soccer federation on Friday that it could have its stadium closed after play was interrupted during its match against Real Madrid.
The federation’s competition committee issued the ruling two days after some fans threw inflatable balls onto the pitch in the 55th minute of the clasico. That caused a brief delay while security guards cleared them away.
The balls were thrown as part of a protest by Catalonia’s separatists inside and outside the stadium.
Security was increased inside the stadium to ensure the game was played without a major incident after police said they were worried about the possibility of a pitch invasion, which did not occur.
Outside Camp Nou, however, protesters burned trash containers and clashed with police, leading to nine arrests and dozens of injuries on Wednesday.
The match was originally scheduled for October but was postponed after days of violent protests in Barcelona and nearby towns following the imprisonment of several leaders of the northeast region's separatist movement.