Strasbourg and Eintracht Frankfurt fans clashed at a tram stop after Thursday night's Europa League match.
AIK hooligans tried to attack rival Maribor fans during their Champions League second qualifying round second leg match on Wednesday.
A brawl erupted between Nantes and Brest fans immediately after Friday's pre-season friendly at the Mane Braz stadium in the north-western French town of Inzinzac-Lochrist.
Hajduk Split fans invaded the pitch to vent their displeasure following the side's 3-1 home defeat to Maltese club Gzira United on Thursday.
Levski Sofia and Cracovia hooligans clashed in a mass fight in Bratislava on Wednesday.
Olympique Safi's home match against Kawkab Marrakech was halted on Tuesday after fans invaded the pitch.
CSA Steaua fans went on the rampage after their side missed out on promotion to the third division with a 1-0 defeat to Carmen Bucuresti on Sunday.
Grasshopper Club Zürich fans forced the side's players to hand over their shirts during Sunday's Swiss Super League match at FC Luzern.
A brawl broke out between Wloclavia Wloclawek and Legia Chelmza fans during their Polish IV Liga match on Sunday.
PAS Giannina fans clashed with riot police during their side's defeat to PAOK on Sunday 5th May.
Dortmund and Schalke hooligans clashed briefly at the Westfalenstadion after their Bundesliga match on Saturday.
FAR Rabat fans clashed with cops during their side's match against RS Berkane on Wednesday.