RIO DE JANEIRO (AP) -- FIFA said Thursday it was investigating claims that Mexico fans chanted anti-gay slurs during their opening match against Cameroon.
FIFA said ''disciplinary proceedings were opened against Mexico for improper conduct of spectators'' last Friday in Natal.
The same chants were heard during Mexico's second match against Brazil in Fortaleza on Tuesday. They are often heard at matches is Mexico, usually as a keeper takes a goal kick.
''FIFA takes a firm, zero-tolerance stand against any form of discrimination or racism,'' FIFA said in a statement.
FIFA President Sepp Blatter and Brazil President Dilma Rousseff have pledged to use the World Cup as a platform to fight racism and discrimination.
Fare, the European fan-monitoring group, has also alerted FIFA to far-right banners displayed by Croatia and Russia fans inside stadiums.
FIFA spokeswoman Delia Fischer said no inquiry had been opened against any country other than Mexico.
Fischer said FIFA would make no other comment about the case because the investigation was ''on-going.''
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