Jail cells could be installed inside Italian soccer stadiums if fan violence continues to escalate, officials said.

“If it’s necessary, let’s build cells in stadiums to jail immediately whoever commits a crime,” Italian league president Antonio Matarrese told reporters on Thursday.

The idea comes after a violent opening weekend to the Serie A season. Napoli fans caused a riot on a train to Rome, and more violence broke out when the train reached the capital for the Roma-Napoli game at the Olympic Stadium.

Two seasons ago, a police officer was killed outside Catania’s stadium in riots following a game against Sicilian rival Palermo. Last year, a Lazio fan was killed by police at a highway rest stop near Florence.

The Italian government unveiled an new ad campaign against soccer violence on Thursday — with spots to be broadcast on TV and stadium screens.

“We will continue to fight against violence without letting our guard down,” Matarrese said. “[Club] presidents are doing the impossible. Let’s not forget that some go around with security escorts because they face opposition from violent fan groups.”