Nine people were arrested in Kortrijk city centre on Saturday evening after a series of confrontations between rival groups, local police said.
Police in the Vlas zone, which covers Kortrijk, Kuurne and Lendelede, had already stepped up vigilance after leaflets circulated in recent days calling for a protest in Kortrijk.
That original call appeared to attract little support. However, a counter-group emerged that said it wanted to “protect” the city from the announced youth protests.
At the same time, a pro-Palestinian demonstration was taking place in the city centre.
The unrest began at about 19:00, when tensions flared between the counter-group and pro-Palestinian demonstrators.
Police spokesman Thomas Detavernier said the clashes turned into a cat-and-mouse game, with the groups repeatedly seeking each other out at different locations across the centre.
Several incidents involved people exchanging blows.
In connection with the disturbances, police arrested nine young men.
