More than 200 people have been arrested after football fans clashed with North African youths in Brussels.
Police said on Saturday they believe the fighting a day earlier was organised over the internet after a website called for an "an attack on all white fans of Anderlecht footclub".
Belgian police said the website ahd informed users where and when the violence would take place against the club, which won the Belgian Cup Final last Sunday.
Fourteen police officers and 10 other people were injured in the violence.
Crowds gassed
Belgium state television reported that 14 policemen were also injured after hundreds of youths turned on a police contingent as it sought to prevent a street fight between fans and local youths.
Police came under a barrage of stones and bottles, while officers used water cannons and tear gas to disperse the crowds.
Gerald Noon, the head of the Anderlecht police force, said: "There were clashes between the club fans and a group of North Africans after the match. We knew that they were looking for confrontation."
"We managed to stop them but then they turned towards us."
Many houses, shops and cars were destroyed in the violence.