Geneva - UEFA have imposed a raft of sanctions after racist incidents in the Champions League and Europa League.
In a statement, UEFA said that it had ordered the partial closure of the stadiums of Hungarian club Debrecen, Romanian side Steaua Bucharest, Slovenians Maribor and Georgians Chikhura Sachkhere.
The one-game penalties will apply to the four clubs' next European competition matches.
The incidents occurred during their Champions League and Europa league matches last month.
Debrecen beat North Irish club Cliftonville 2-0 in their Champions League second qualifying round second leg on July 22.
Having gone through to the third round and beaten BATE Borisov 1-0 in the first leg, Debrecen could cement their European campaign during the second leg in Belarus.
The partial stadium closure will therefore apply to the Champions League playoffs, if they make it.
Steaua Bucharest, meanwhile, defeated Norwegian visitors Stroemsgodset 2-0 in their Champions League second leg.
They host Kazakh side Aktobe in the third qualifying round, after a 2-2 draw in the first leg.
Maribor also notched up a 2-0 win against Bosnian side Zrinjski in their racism-marred match.
Having reached the third round, they edged Maccabi Tel Aviv 1-0 in the first leg at home.
In the second leg, they face Maccabi in Cyprus, after the match was shifted by UEFA because of security concerns in Israel.
Chikhura Sachkhere drew 0-0 with Turkish side Bursaspor in their Europa League second qualifying round first leg in July 24.
Having gone through to the third qualifying round, they will be punished during their home second leg against Neftci from neighbouring Azerbaijan, with whom they drew 0-0 in the July 31 first leg.
"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," UEFA said.