FIFA, the international governing body for football, has asked Iran's soccer federation to respond to media reports that players who wore green wrist bands in solidarity with the political opposition have been punished.

FIFA wrote to the Iranian federation "asking for information, and seeking clarification, regarding current media reports related to Iranian national team players," FIFA said in a statement Thursday.

Several team members wore wrist bands in the color of defeated presidential candidate Mir Hossein Mousavi's opposition movement before a June 17 World Cup qualifying match against South Korea in Seoul.

According to Iran's semiofficial ISNA news agency two players, Mehdi Mahdavikia and Ali Karimi, have since resigned from the team for personal reasons.

But Britain's Guardian newspaper and others have reported that as many as four players were permanently banned from the team by government authorities. The reports could not be verified immediately.