Fans Riot At Genoa Game

Apparently, over the weekend, Genoa fans got fed up with the club as they go down to a 4-0 scoreline. A group of fans occupied the tunnels, and threw smoke bombs onto the field, causing the game to come to a halt, and the players being trapped on the field. From there, the fans demanded all players to take off their shirts and give it to the fans, because they did not deserve to wear it. Eventually, they agreed, and the captain went around taking every player's shirt, to give to the fans. However, the goalkeeper and another player refused to give their shirts up, and the player went over to the tunnels to talk face to face with a fan group leader. He convinced the fans to let them finish the game (saying they would get suspended and lose points for not getting on with it), and they managed to finish it off 4-1.
This was a horrible act from the fans, what do you guys think about this? Do the fans have a right to do this? Should the police have stepped in?