A Rapid București fan snatched a banner from Rapid CFR Suceava fans during their Liga II match at the Areni Stadium on Sunday.
Manchester United and Liverpool fans clashed in the stands at Old Trafford.
Guaraní Antonio Franco fans fought among themselves in the stands during their Torneo Federal A match with Sol de América on Monday.
Fortaleza and Sport Recife fans clashed during the half-time.
FK Sloboda Tuzla and FK Sarajevo fans fought inside the Tušanj Stadium during their cup tie on Wednesday.
Tottenham and Arsenal fans clashed ahead of the north London derby.
PAOK's Greek Cup semi-final against Olympiacos was abandoned on Wednesday as home fans clashed with riot police on the Toumba Stadium pitch.