UEFA has punished three Champions League clubs for racist behavior by fans at matches last month.
UEFA says Steaua Bucharest, Debrecen and Maribor must close stadium sections at the next Champions League or Europa League match they host.
Steaua's sanction takes effect Wednesday. Two sections of the National Arena will shut against Kazakhstan champion Aktobe in a third qualifying round, second-leg match.
UEFA's disciplinary panel acted on reports of racist incidents when Steaua beat Norway's Stromsgodset 2-0 on July 23.
Debrecen of Hungary must shut sector B of its ground after fans showed an "illicit banner" during a match against Northern Ireland's Cliftonville.
Slovenia's Maribor must close sector 'Jug' of its stadium after racist behavior when Zrinjski of Bosnia-Herzegovina visited.
Debrecen and Maribor play away in second-leg matches Tuesday.