Mexican actor Diego Luna is speaking out against homophobic chants during World Cup matches. Fox News Latino reported that the award-winning actor and producer said it is regrettable that homophobic terms like "puto," a common cry heard at Mexico's soccer stadiums, are used to insult players during games.

Some say the word means weak or coward and isn't directed at gays, but it is clearly meant to mock an opponent as weak and unmanly.

"I went to the [2006] World Cup in Germany, and I did hear [that cry]," the actor said in an interview with MVS radio. He said he never joined in because he couldn't be proud of doing so.

"Soccer is a reflection of what we are in many ways," he said. "We live in a classist, racist, homophobic society into which we are very assimilated, that's all. I'm not really proud of that."

On Thursday, the International Federation of Association Football, or FIFA, opened a disciplinary inquiry into the chants Mexican fans yelled during World Cup games against Cameroon and Brazil.

ESPN told Outsports it will try to prevent the chants from being heard on-air Monday when Mexico plays Croatia. The network says it is sensitive to the chant.

Andres Aradillas-Lopez, an economics professor at Penn State University, was born in Mexico and said he told Outsports the slur disgusts him.

"I heard them during the Cameroon game and also today against Brazil. Every single time the opposing goalie had a goal kick, they chanted ['puto']," Lopez said. "The media should make a bigger deal out of this and publicly shame that country and its fans. No other country in the world does this, and it would be unacceptable in any U.S. stadium."

Mexico national team coach Miguel Herrera didn't take the chants seriously, saying, "We have nothing to say; we're with the fans. They do it to put pressure on the other team's goalkeeper -- I don't think it's that serious."

FIFA statutes state that discrimination -- by players, coaches or fans -- against any country, individual or group for their race, skin color, ethnic origin, nationality, sex, language, religion or other factor is prohibited.

Luna has played LGBT characters in his films, including "Y Tu Mama Tambien" and "Milk."

LGBT activists have been using the World Cup to draw attention to anti-gay killings that have plagued Brazil. Last year there were 313 anti-gay killings in the country, according to watchdog Grupo Gay de Bahia.