Euro 2012 -- co-hosted by Poland and Ukraine -- has gotten under way in Warsaw.
The three-week-long football competition started with an opening ceremony on June 8 in front of a 50,000-strong crowd at Warsaw's National Stadium.
Following the ceremony, co-hosts Poland drew 1-1 with Greece. In the second match of the day, Russia crushed the Czech Republic 4-1 in the Polish city of Wroclaw.
It was the first of 31 games at eight venues in the two countries.
The final is scheduled for July 1, in the Ukrainian capital, Kyiv.
Earlier, the European football governing body UEFA said in a statement it had been informed that "isolated" racist incidents occurred as people watched a training session of the Dutch team in Krakow, Poland.
It acknowledged reports of the racist abuse of Dutch black players, but said the association had not received a formal complaint from the Dutch team.
The Dutch team's captain Mark van Bommel however said hundreds people who watched the training in Krakow on June 6 targeted the team's black players with noises and gestures imitating monkeys.
The Netherlands' training session in Krakow was watched by some 25,000 people. Krakow is not hosting any Euro 2012 matches.
Brommel said that if there was a repeat during a Euro match, the Dutch team would ask the referee to stop the game.
'A Small Minority'
The incident has renewed concerns about possible racism from fans, following a recent BBC documentary highlighting racist behavior by Polish and Ukrainian football supporters.
A Polish fan, Wojciech, said the problems were caused by a very small minority.
"The problem is that it is always generated by a very small, limited number of... supporters," he said. "As you know, they are very loud, so they are visible even if there are a very small number of them. And I think it [puts] a bad light on [all] of the supporters from Poland."
Polish and Ukrainian officials have sought to dismiss concerns about potential racist abuse during the championship.
In its statement on June 8, UEFA said the association would have zero tolerance for any display of racism at the tournament.
Separately, numerous European officials have called for a boycott of matches in Ukraine in protest over former Prime Minister Yulia Tymoshenko's seven year prison sentence on abuse of office charges, which they say are politically motivated.
With reporting by Reuters, AP, AFP