Thousands of protesters gathered in Brussels, including Filip Dewinter (center), a leading figure in Vlaams Belang, a right-wing Flemish nationalist party.
But the protests soon began to turn ugly. Here demonstrators are trying to topple an EU flag outside the European Commission headquarters.
Mounted police attempted to control the crowds.
Tensions escalated as protesters ripped up street signs and metal railings as they clashed with police. Some demonstrators threw items at police.
next slide will load in 15 secondsSkip AdSkip AdThis man launched a traffic sign at law enforcement.
Police responded with a water cannon as they attempted to take control of the situation.
One activist was hit the face by the jet of water.
Pepper spray was also deployed by police.
Some people were detained.
next slide will load in 15 secondsSkip AdSkip AdAs the situation calmed, the damage to the streets of Brussels was visible.