Partizan Belgrade's Everton Luiz left the field in tears following racist chants in February. STR/AFP/Getty Images

BELGRADE, Serbia -- UEFA president Aleksander Ceferin has warned the Serbian clubs that they could be kicked out of European competitions because of fan riots and racist chants.

"Serbia is in serious danger of being kicked out of competitions at some point," Ceferin said. That would be a catastrophe for Serbian football."

Speaking of the hooligans behind the trouble, Ceferin added: "It must be made clear that those people no longer can enter stadiums."

Fan violence in and outside stadiums and racist outbursts have been frequent in Serbia.

A Brazilian playing for Partizan Belgrade left the field in tears after persistent racist chants during a game in February.

Last week, two Russian fans were hospitalised with serious injuries after being stabbed following a friendly between Red Star Belgrade and Spartak Moscow.