A Deportivo La Coruna supporter has died following violent clashes between fans before the La Liga game away at Atletico Madrid on Sunday.
The unnamed 43-year-old was reportedly taken out of a river near the Vincente Calderon Stadium suffering from cardiac arrest, hypothermia and head injuries, before passing away in hospital.
Atletico president Enrique Cerezo, speaking before the death of the supporter was announced, is quoted by BBC Sport as saying: "I want to say that this has nothing to do with football. These are radical groups who meet up and these are the consequences."
Meanwhile, Deportivo president Tino Fernandez expressed his dismay, telling reporters: "It's tragic news. I want to express our vehement opposition to violence."
Eleven other people, including a female police officer, were treated for injuries during the fighting, while 20 alleged troublemakers were taken into custody.