CSKA Moscow on Saturday dismissed a report that their fans had chanted racist abuse at Arsenal's black players during a Europa League quarter-final match on Thursday.
A Reuters photographer at the game, which ended in a 2-2 draw, heard dozens of home supporters make monkey chants at Arsenal's Danny Welbeck and Alex Iwobi when they neared a particular section of the stands as the ball went out of play.
On Saturday, an individual at Arsenal indicated that the club had not made a complaint about racial abuse.
The chants were repeated when Welbeck celebrated his 75th-minute goal, which brought Arsenal back into the game from 2-0 down.
A third Arsenal player who did not come off the substitute's bench was targeted with the same chants after the final whistle as he jogged to warm down on the pitch at the CSKA Arena. The player, who Reuters was unable to identify, was also black.
CSKA, who did not respond to requests for comment on Friday, said in a statement on Saturday that they were "outraged" by what they called a "slanderous" report.
"The match, which will be remembered for its bright soccer, was held in an excellent atmosphere," the CSKA statement said, characterizing the report as a "cheap provocation.".
Welbeck and Iwobi did not reply to messages sent to their verified Instagram accounts.
Russia has pledged to crack down on racism in sport as it faces increased scrutiny before it hosts the soccer World Cup from June 14 to July 15.
UEFA told Reuters on Friday that no racist behavior had been reported to it by match officials at the game.
However, UEFA said it had opened disciplinary proceedings against CSKA for infractions, including throwing objects and setting off fireworks, that were not connected to racist or discriminatory behavior.
"UEFA opened the case, not us," CSKA spokesman Sergei Aksyonov said on Saturday. "There were no fireworks, and as for the objects, there were only papers carried by the wind."
Arsenal's draw with CSKA saw them reach the Europa League semi-finals 6-3 on aggregate after a 4-1 win in the first leg. They face Spanish club Atletico Madrid in the last four.