WARSAW, Poland – UEFA has been informed that there was racist chanting at the Netherlands team training session this week after some players reported hearing "monkey noises."
"UEFA has now been made aware that there were some isolated incidents of racist chanting," UEFA said in a statement.
Netherlands captain Mark von Bommel has been quoted as complaining about racist chants at the end of the stadium during a training session that was open to the public on Wednesday at Wisla Krakow’s stadium. About 25,000 spectators were in attendance.
"Open your ears. If you did hear it, and don't want to hear it, that is even worse,” Van Bommel told Dutch reporters on Thursday, according to Reuters.
"He has heard noises and by moving to the other side, we nipped it in the bud," the Dutch federation said Friday.
Coach Bert van Marwijk, Dutch officials and many of the press did not hear any racist abuse during Wednesday's session, but a team spokeswoman told Reuters, "some players did hear some monkey noises. That is why they moved to the other side of the pitch."
Netherlands teammate Ibrahim Afellay told De Telegraaf newspaper that the jeers had "saddened him."
The Dutch federation said Thursday that it did not file a formal complaint to UEFA.
Racism has emerged as a key issue for the Euro 2012 tournament being co-hosted by Poland and Ukraine.
A recent British television documentary, entitled "Stadiums of Hate," fueled concerns about fans' behavior at club matches. The program was shown in Poland earlier this week and the issue dominated questions at the first news conference of UEFA President Michel Platini at the tournament.
Platini promised that referees will stop matches if players suffer racist abuse. But he also warned players they would be shown a yellow card if they acted alone by walking off the field.
"UEFA has a zero tolerance policy when it comes to discriminatory behavior and has given the power to referees to stop matches in case of any repeated racist behavior," UEFA said Friday
The sole black player on the Czech Republic's team, Theodor Gebre Selassie, said he hoped racism wouldn't flare up in the stadiums.
"We don't know yet what the situation will be like at the stadiums," he said, adding that he would not walk off the field. "I'm not ready to give up. I definitely won't leave. I'll stay until they throw stones at me."
"If it happened I would walk off the pitch and return home. We are in 2012," Italy's Mario Balotelli told Reuters last month.
He also reportedly said he would "kill" anyone who threw a banana at him in the street during the tournament.
The Associated Press contributed to this report.