UEFA today acknowledged Holland's black players were the victims of racist abuse during a training session in Krakow.

Members of Bert van Marwijk's European Championship squad were allegedly subjected to monkey chants during an open training session on Wednesday, with captain Mark van Bommel yesterday branding the incident "a real disgrace".

Having initially been satisfied by the Dutch Football Association's belief that the abuse was not racially motivated, UEFA announced this morning they had been made aware of "isolated incidents of racist chanting".

European football's governing body said in a statement: "UEFA has now been made aware that there were some isolated incidents of racist chanting that occurred at the open training session of the Dutch team.

"UEFA has not yet received any formal complaint from the KNVB."

Bert van Marwijk's side begin their Euro 2012 Group B campaign against Denmark on Saturday.

The Dutch coach was quoted as saying of the incident: "At least now we know what we can encounter here."

The issue of racism has been a hot topic in the build-up to the tournament, with a much-publicised BBC documentary raising concerns over the conduct of some fans in the host nations.

UEFA president Michel Platini has confirmed referees have been instructed to call a halt to matches at this summer's tournament if a player is racially taunted.

Yet the Frenchman also warned any player who left the field unilaterally in protest over abuse from the stands would be yellow carded.

Italy and Manchester City striker Mario Balotelli had earlier said he intended to do exactly that if he found himself being racially abused.

Former England centre-back Sol Campbell, meanwhile, was compelled to advise fans to avoid the tournament after seeing the Panorama images of supporters in Ukraine giving Nazi salutes and taunting black players with monkey noises.

Meanwhile, the families of black England players Theo Walcott and Alex Oxlade-Chamberlain have declined to travel to watch the matches because of fears over racism.