RIOTS broke out in the centre of Brussels this evening with projectiles thrown at police and cars vandalised.
Local police called for the Federal police to step in after violence escalated rapidly and young people attacked officers with rocks and knives.
Local news site RTL said: "Crowd movement in the Place de la Monnaie in Brussels, traffic had to stop because people were running through, at least 200 to 300 people seemed to want to run away from each other. Police sirens have been heard continuously since ".
An angry crowd of hundreds gathered in Place de la Monnaie in the city after a Youtube star called his fans to meet in the area for a music video.
Rapper ‘Vargasss 92’ asked his fans to meet him at the square at 4pm.
But the situation quickly deteriorated.
Local police spokesman Olivier Slosse said a police team tried to approach the rapper in the square, but the crowd turned on officers and began throwing rocks at them.
The police were forced to withdraw from the scene amid the violence.
Riot police later attended the scene to calm the disturbance.
The star took to Snapchat to plead with fans to stay calm, but the angry mob began throwing gates as well as stones.
Some young people reportedly have knives and sticks.
Local media reports several people have now been arrested.
Twitter user Shane wrote on the social media site that “many tourists thought there had been a terrorist attack”.
Other witnesses reported seeing youths smashing cars with iron bars.