Uefa opened disciplinary proceedings against Russia on Saturday night over the behaviour of fans during their match against the Czech Republic.

The decision followed reports that the Czech's only black player, Theo Gebre Selassie, was the target of monkey chants during the game in Wroclaw, with fans also seen displaying far-right "Russian Empire" flags. In a separate incident, four stewards needed hospital treatment after being attacked by a group of Russian fans inside the stadium.

Uefa – under pressure over their slow response to the racist abuse aimed at Holland's players during a training session in Krakow on Wednesday – said they would hold an immediate investigation.

"Having looked at the security reports and available images, disciplinary proceedings have been opened against the Football Union of Russia," said a Uefa statement. "This relates to the improper conduct of its supporters, the setting-off and throwing of fireworks and the display of illicit banners. The control and disciplinary body will review the case on Wednesday June 13.

"In addition, regarding reports of alleged abuse directed at Czech Republic players from Russia fans, Uefa is investigating this further and is working with Football Against Racism in Europe to collect more evidence."

The chief executive of FARE, Piara Power, had earlier confirmed that one of the group's match observers had reported "fleeting" racist abuse aimed at Selassie from a "small section of the crowd", though added: "It may not be easy to pull together evidence for a case to be brought."

The violence, footage of which appeared online, included one steward being punched to the ground and then kicked before the fans walked away. Police said the fans appeared to have become aggressive when stewards tried to detain a man who had thrown firecrackers towards the pitch. No arrests were made, but footage of the incident is being reviewed.

A Russia team spokesman, Nikolai Komarov, said the federation declined to comment on the details of the reported incidents, but added: "The federation has many fans. You don't have control over them all."