WARSAW, Poland (AP) - Racism and violence involving Russia's fans have marred the start of the European Championship and confirmed fears that Euro 2012 could be a troubled tournament.
Fans of co-host nations Poland and Ukraine had been seen as a potential source of racial abuse, following a damning investigation by the BBC. Instead, Russia became the main security issue after evidence emerged Saturday of incidents at the Wroclaw stadium where it beat the Czech Republic 4-1 on Friday.
Czech defender Theodor Gebre Selassie, who is black, was the target of racial abuse reported by official fan monitors to Euro 2012 organizer UEFA.
Russia supporters later fought stadium stewards in an attack seen worldwide after footage circulated online. Wroclaw police said four people were treated in a hospital.
A potentially volatile clash between Russia and Poland looms in Warsaw on Tuesday - a Russian national holiday with fans planning to march from the city center to the stadium.
A Russia team spokesman, Nikolai Komarov, said the federation declined comment on details of the reported incidents.
However, Komarov told The Associated Press in a telephone interview: "The federation has many fans, you don't have control over them all."
Saturday's reports tarnished what was a successful opening day for Euro 2012. Two compelling matches followed constant negative headlines regarding social and political issues in the eastern European neighbors, including monkey chants aimed at Netherlands players during a public practice Wednesday at Krakow, Poland.
UEFA has pledged zero tolerance of discrimination during the three-week tournament. To help achieve this, it asked the Football Against Racism in Europe (FARE) fans' network to send two monitors to each match offensive banners, chants and behavior in stadiums, and report to UEFA within 24 hours.
On Saturday, FARE said it identified verbal insults targeted at Gebre Selassie, whose father is Ethiopian.
"There was some suggestion that the Czech defender went to take a corner and had a few problems," FARE executive director Piara Powar told the AP.
Fans also displayed a nationalist "Russian Empire" flag which "we take as evidence of far-right sensibilities," Powar said in a telephone interview.
Powar said FARE officials aimed to provide footage of Gebre Selassie being abused.
"We are trying to get that evidence, and it's not always possible to capture it on film," he said.
Still, film was available showing some Russian fans attacking security staff.
Polish police said the four injured stewards "were not badly injured, and security footage was being studied to identify those involved.
UEFA said in a statement that "around 30 fans" attacked the stewards in a "brief and isolated incident.
"The situation was quickly and efficiently brought under control," the statement said, though footage appeared to show attackers walking away from the scene.
The 16 competing teams' national federations are responsible for their fans' actions. They would be fined by UEFA before facing possible expulsion from Euro 2012 for repeated offenses.
Four years ago, UEFA fined Croatia 20,000 Swiss francs (then $19,600) for its fans' neo-Nazi flags and chants during a Euro 2008 quarterfinals loss against Turkey in Vienna, Austria. On Sunday, Croatia plays Ireland in Poznan, Poland.
"We don't expect UEFA to act on every report," Powar acknowledged. "It's tough to evidence everything that could be admissible in a hearing."
Powar also expressed concern at possible nationalist flashpoints in Tuesday's march, even if Russia fans are denied permission by Warsaw city authorities to go ahead.
"There is a feeling that the Russians will do it anyway," he said. "We have got a lot of people out and we will be looking."
Powar said Polish feelings were agitated by Russia basing its players in a Warsaw hotel neighboring the country's presidential palace, close to a shrine commemorating the Smolensk air disaster.
Poland's then state president Lech Kaczynski was among 96 people who died on April 10, 2010 when their airplane crashed in Russia.
Conspiracy theories persist in Poland that Russia was complicit in the crash.
Concerns of racism at Euro 2012 were fueled last month by a British television program, entitled "Stadiums of Hate," showing discrimination and violent incidents at recent club matches in Poland and Ukraine. It was broadcast in Poland this week.
Racism marred the Netherlands' preparations for its opening match Saturday against Denmark after several spectators made monkey noises at players during a squad practice in Krakow, Poland, which was attended by 25,000 people.
UEFA President Michel Platini has said that his organization has given referees the power to stop and abandon matches if crowds racially abused players.
After Italy forward Mario Balotelli threatened to leave the field if abused, Platini warned players they would get yellow cards for acting alone to protest.
Gebre Selassie said this week that he would not walk off the field.
"I'm not ready to give up," said the 25-year-old player. "I definitely won't leave. I'll stay until they throw stones at me."
Associated Press writers Mike Corder and Vanessa Gera contributed to this report
Graham Dunbar can be reached at www.Twitter.com/gdunbarap