Fenerbahçe fans clashed with Dutch riot police in the centre of Amsterdam ahead of their Europa League match against Ajax on Thursday.
Members of the Delije attacked Dinamo Zagreb's Bad Blue Boys at Athens International Airport this afternoon.
Aris fans clashed with riot police inside the ground during the first half of their third division match with Nestos Chrysoupolis on Sunday.
Alemannia Aachen and Rot-Weiss Essen fans clashed at the Tivoli Stadium during their Regionalliga West match this afternoon.
Slask Wroclaw hooligans attacked Sevilla fans outside a bar in Shambles Square in Manchester city centre on Wednesday afternoon.