A Deportivo La Coruna supporter has died following violent clashes between rival fans ahead of Sunday's Primera Division match between Atletico Madrid and Depor at the Vicente Calderon stadium, it has been confirmed.
The man, who has not been named officially, was still alive when firefighters pulled him out of the Manzanares river near Atletico's home ground.
In a critical condition, he was taken to the San Carlos Clinic in Madrid by ambulance but died shortly after.
The club confirmed the death of the fan, known as 'Jimmy', on their Twitter account.
"A patient, a male in his 40s, arrived at the hospital with cardiac arrest and suffering from hypothermia. Despite lengthy attempts to resuscitate him, he could not recover from the cardiac arrest and died," Isabel Diez, press officer at San Carlos Clinic, told Press Association Sport.
"We don't know the exact causes as only an autopsy can determine."
Trouble flared in the Madrid Rio public park, close to the stadium, ahead of a match that began at midday local time (1100GMT).
According to reports in Spain, groups of Atletico and Deportivo hooligans gathered at the site where the violence began at around 9am.
Nuestras más sinceras condolencias y apoyo a los familiares y amigos de "Jimmy". D.E.P. #FútbolSinViolencia
— R.C.Deportivo (@RCDeportivo) November 30, 2014
Spanish league authorities had wanted the match - which was won 2-0 by Atletico - to be postponed but said it was not possible.
Prior to confirmation that the supporter had died, the Liga de Futbol Profesional announced on its website: "The LFP condemns the incidents that took place on Sunday morning outside the Vicente Calderon stadium before the week 13 match in La Liga between Atletico Madrid and Deportivo La Coruna.
"The LFP has been firm in its intention to suspend the game but this was not possible. The association is working with Fans United, the national police, all the clubs and all the public limited sports companies to end violence, racism, xenophobia and intolerance in professional football."
Atletico issued their own statement, saying: "Atletico Madrid strongly condemns the incidents in the area of Madrid Rio in the hours before the match against Deportivo La Coruna.
"The values that promotes sport should prevail over any rivalry and together we must fight against the scourge of violence."
Police have made 14 arrests so far.
The Spanish Football Federation (RFEF) also strongly condemned the violence and offered their condolences to the family of the man who died.
A statement from the RFEF said: "The RFEF offers their assistance to all those affected by the incidents that have taken place in the vicinity of the Vicente Calderon stadium.
"The RFEF wishes to express its deepest condolences to the family, the fans and the Deportivo La Coruna board, as well as to assist all of them after the death of the fan of their team which happened as a consequence of the serious incidents that took place this morning in the vicinity of the Vicente Calderon stadium and that were carried out by radical groups.
"The RFEF strongly condemn these types of incidents that have nothing to do with football and expresses its complete rejection of violence.
"The RFEF will continue to work with all its energy and all its means, as it has done so up to now, with the aim of avoiding these lamentable incidents from happening again."
