Soccer is a matter of life and death for European fans, literally.

A police officer suffered cardiac arrest during fights between combative supporters, known as “ultras,” of Spanish club Athletic Bilbao and Russian club Spartak Moscow, according to reports from the Basque police force.

Inocencio Alonso Garcia, 51, collapsed when a nearby Russian ultra threw a flare, the Royal Spanish Football Federation said in a statement. He later died at the local hospital.

The fighting broke out just before the second leg of the round-of-32 Europa League clash between the two clubs in the streets surrounding San Mamés Stadium in Bilbao, Spain.

Nine were arrested, and two Russian fans were taken to the hospital as fans brought weapons such as knives and batons to the game, according to police. Videos show riot police attempting to quell the violence as rival supporters shot fireworks, threw glass bottles and attacked each other with weapons.

VÍDEO. Incidentes con los aficionados rusos. pic.twitter.com/cPFkoeBNrK

— Radio Bilbao (@radiobilbao) February 22, 2018

After the game, Athletic Club tweeted their condolences.

Our deepest condolences to the family and companions of the deceased agent today. Athletic Club shows its strongest rejection of the violence generated around football. #athlive#UEL

— Athletic Club (@Athletic_en) February 22, 2018

Spain’s Prime Minister Mariano Rajoy condemned the violence in a tweet, “My condolences to the family and colleagues of the deceased agent in Bilbao and my recognition of the Ertzaintza for their efforts to protect those who know how to enjoy the sport. I strongly condemn the violent incidents.”

The incident drew attention from Sergio Ramos, Spanish national team and Real Madrid captain, who tweeted, “Football, sport and society cannot remain indifferent to violence, fear and the loss of life. We must force change.”

El fútbol, el deporte y la sociedad no podemos permanecer indiferentes ante la violencia, el miedo y la pérdida de vidas. Hay que actuar.Hay que impulsar un cambio.
Football, sport and society cannot remain indifferent to violence, fear and the loss of life. We must force change.

— Sergio Ramos (@SergioRamos) February 23, 2018

The incident may have future implications as the Bilbao mayor Juan Mari Aburto has threatened to pull out as a host city during the Euro 2020 if UEFA, European soccer’s governing organization, fails to take action against violence surrounding soccer.

Russian fans made a name for themselves during Euro 2016 after nearly earning their team expulsion from the tournament following bouts of violence in Marseille, France. Given that Russia is set to host the 2018 World Cup this summer, more issues may arise despite FIFA’s steadfast confidence in Russian security.

Bilbao lost the game 1-2, but will advance to the next round of UEFA’s second-tier competition on 4-3 aggregate.