CSKA Moscow must close part of their stadium for their next Champions League home game following the racist abuse hurled at ManchesterCity's Yaya Toure by the Russian club's fans last week, UEFA said on Wednesday.
The Ivorian said he was racially insulted during City's 2-1 match at CSKA last week and added that black players could boycott the 2018 World Cup in Russia if the country does not tackle the issue.
UEFA's disciplinary panel ordered the closure of sector D of the Arena Khimki for the match against Bayern Munich in Moscow on November 27.
"The fight against racism is a high priority for UEFA. The European governing body has a zero tolerance policy towards racism and discrimination on the pitch and in the stands," said UEFA in a statement.
"All forms of racist behaviour are considered serious offences against the disciplinary regulations and are punished with the most severe sanctions."
Piara Power, executive director of Football Against Racism in Europe (FARE), said on Twitter: "UEFA CSKA sanction is a clear signal. Racism and other forms of discriminatory abuse will be punished. Education is only answer long term."
Toure reported the incidents to the referee during the game but no action was taken even though match officials have been told to follow UEFA's guidelines, set down in 2009, in such cases.
The guidelines call for play to be stopped and a warning to be broadcast over the public address system. Ultimately, officials have to power to call off the game if the abuse continues.
UEFA president Michel Platini ordered on Friday an internal inquiry into why Romanian referee Ovidiu Hategan and his assistants did not follow them. CSKA said they were "surprised and disappointed" by Toure's allegations of racism.
Toure, who speaks Russian after spending two years playing in Ukraine for Metallurg Donetsk, said the abuse he experienced in Moscow was worse than anything he had encountered in Ukraine.
Under regulations introduced by UEFA this season to combat racism, a partial stadium closure is the minimum sanction for racist behaviour.
A second offence by supporters will lead to a full stadium closure for the following European match and a 50,000 euro fine. Racist behaviour by players or officials leads to a minimum 10-match ban.
Lech Poznan, Piast Gliwice and Dinamo Zagreb have been forced into partial closures this season for racist behaviour by supporters. Honved had to play two home games behind closed doors.
Legia Warsaw were ordered to play one home match behind closed doors in the Europa League.
Image: Yaya Toure of Manchester City
Photographs: Shaun Botterill/Getty Images