Zbrojovka Brno and Banik Ostrava fans briefly clashed in the stands at half-time during a Czech First League game on Friday.
Brescia and Cagliari fans clashed ahead of their pre-season friendly match on Saturday.
Luzern and Osijek fans clashed outside a bar in the Swiss city of Lucerne ahead of their Europa League tie on Thursday.
Fans of Egypt’s Zamalek caused a riot at the Borg el-Arab Stadium on Sunday night as their team crashed out of the African Champions League.
Vasco da Gama fans clashed with military police in and outside the Sao Januario stadium following their side’s defeat to arch-rivals Flamengo on Saturday.