At least 100,000 workers took to the streets of Brussels on Thursday to protest the Belgian government’s free-market reforms and austerity measures.
At least 14 people were injured when protesters clashed with the police.
Protesters pelted police with stones and fireworks, overturning cars or setting them on fire. Police used tear gas and water cannons to disperse the demonstrators.
The workers were protesting plans by the country's new center-right government to increase the pension age from 65 to 67, freeze wages and cut public services.
The government says it must implement austerity measures to keep the budget deficit in line with European Union requirements. It also insists that businesses need more tax breaks to compete in the global market.
Trade unions have objected to the government plans, saying they undermine Belgium's welfare state. The unions have announced they will push their demands forward during a several-week long campaign that will culminate in a general strike on December 15.