Hundreds of yellow-vested protesters calling for the resignation of Belgian Prime Minister Charles Michel marched overnight on the European quarter of Brussels, as the movement that started in France made its mark in Belgium and the Netherlands.
Police used pepper spray and scuffled with a small group of protesters who tried to break through their barricade blocking access to the European Parliament and the European Union's other main institutions.
The rallies, which started at different locations around the city and converged on the European quarter, have disrupted road and rail traffic on one of the busiest Christmas shopping days of the year.
Walking behind a banner reading "social winter is coming," some protesters called on Michel and French President Emmanuel Macron to resign.
Dozens of people were searched at stations and police have warned people to stay away from the area.
Hundreds of police officers have been being mobilized in Brussels.