Atletico Madrid have issued a public apology for the offensive chanting by a section of their fans about deceased Sevilla defender Antonio Puerta during Sunday's match against the Andalusian side at the Vicente Calderon stadium.
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Puerta died in August 2007 at the age of 22, three days after suffering a cardiac arrest during a league game between Sevilla and Getafe.
A statement on the Atletico website read: "Atletico Madrid deeply regrets the chants made against the figure of Antonio Puerta during last Sunday's game at the Vicente Calderon stadium.
"Our club expresses its deep disgust at such chants and apologises to the family of the late player, to Sevilla and to football in general.
"At Atletico Madrid we support respect in football and we hope that these types of incidents don't happen again either in our stadium or in any other ground.''
Atletico president Enrique Cerezo said on Marca TV: "I apologise to everyone connected with Sevilla and to the family of Antonio Puerta. They must know that the people who sang this are a minority who have nothing to do with football or sport.
"It's sad and painful to hear these songs at a football ground about a person who has been a great sportsman and who is no longer with us.''
Atletico's apology comes at the same time that Premier League clubs Tottenham and Arsenal have pledged to act on the offensive chanting which marred Sunday's north London derby at White Hart Lane.
Sections of the home crowd taunted Arsenal manager Arsene Wenger, while some away supporters were widely condemned for mocking the deadly gun attack on the Togo team bus in January 2010 which Emmanuel Adebayor survived.