Fans caused trouble at the MDCC Arena during Sunday’s German Cup tie between Magdeburg and Eintracht Frankfurt.
Rijeka fans were attacked by local fans before the game.
A hooded hooligan attacked a goalkeeper during a Swedish top-flight match between Jonkoping Sodra and Ostersund on Monday, forcing the game to be abandoned.
Unia Hrubieszów fans were attacked by Górnik Łęczna hooligans during the match.
Austria Vienna and Rapid Vienna fans clashed in the stands at the Ernst Happel Stadium after the final whistle of their Bundesliga match on Sunday.
Sporting and Betis fans clashed near the Algarve stadium ahead of their friendly on Thursday.