Atletico Madrid announced on Monday that they have permanently banned a fan for throwing objects onto the field during Sunday’s intense derby match against Real Madrid. The incident, which occurred at the Estadio Metropolitano, caused the game to be halted for 15 minutes as lighters and other objects were hurled at Madrid players by home supporters.

The heated match, which ended in a 1-1 draw thanks to a dramatic 95th-minute equalizer from Atletico’s Angel Correa, was overshadowed by the unruly behavior from some of the home crowd. Atletico Madrid confirmed they are working closely with the police to identify additional individuals involved in the incident. “Our security department continues to work with the police to identify the rest of those involved, who will be permanently expelled as soon as they are located,” the club stated.

Atletico Madrid reaffirmed their commitment to eradicating violence from the sport. “The club’s firm conviction to eradicate any form of violence and our defense of the values of sport are unquestionable. We will continue to work with all our resources with the aim of eliminating this type of behavior,” the club added.

In response to the incident, Atletico Madrid also announced changes to their stadium regulations. Going forward, fans will be prohibited from wearing clothing or using items that obscure their identity. “The club will imminently incorporate into its internal regulations the prohibition of using any element or garment inside the stadium that prevents distinguishing the face of a person in order to hide their identity,” the 11-time Spanish champions said. Those who violate this rule will be immediately expelled from the stadium.

Atletico Madrid’s next home game will be against Leganes in La Liga on October 20, with the new measures expected to be enforced.