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.
Hajduk Split hooligans attacked members of the Bad Blue Boys outside a bar in Zagreb on Sunday afternoon.
Standard Liege's clash against rivals Anderlecht was abandoned on Friday night because of flares thrown by away fans.
Ajax fans clashed with cops outside the Johan Cruyff Arena ahead of their match against Juventus on Wednesday.
A hand grenade was found at a building used by ADO Den Haag fans on Tuesday morning.
Karlsruher hooligans clashed with their Waldhof Mannheim rivals in the southwest German city of Mannheim on Wednesday.
A Copa Argentina match between Newell's Old Boys and Villa Mitre was abandoned in extra-time on Sunday because of fan trouble.
Sunday's derby match between Panathinaikos and Olympiacos was abandoned after tear gas drifted into Athens' Olympic Stadium and affected players and fans.