Trade unionists called for more and better jobs.
The first demonstrations ahead of this weekend's European Union summit in Belgium have got under way, with tens of thousands of trade unionists marching through Brussels.
The protests have so far been peaceful but police have already arrested 22 people on the Dutch border for carrying objects such as knives, gas-masks and radio scanners to eavesdrop on police frequencies.
Both police and demonstrators say they are committed to keeping the protests non-violent, hoping to avoid the bloody clashes seen in Gothenburg and Genoa earlier this year.
Barricades, water cannons and riot police are being deployed
Up to 4,000 security officers will be on duty over the summit period and barbed wire barricades, water cannons and riot police are being deployed.
Thursday's march was to demand greater involvement of Europe's trade unions in the development of social and employment legislation.
"This is an appeal for a more social Europe," said Waltraud Etz, a spokeswoman for the European Trade Union Confederation, which organised the march.
"We want more jobs and better quality jobs," she said.
There is anger among the Belgian workforce at rising unemployment and the collapse of the national airline, Sabena.
Police and protest groups have been in talks to try to establish some ground rules ahead of the demonstrations.
We hope it will be calm. The only unpredictable factor is groups from abroad
"We hope it will be calm. The only unpredictable factor is groups from abroad," said police spokeswoman Els Cleemput.
But some protest groups are unhappy that the mayor of Brussels refuses to let them demonstrate directly in front of the summit venue, Laeken castle.
"It is a democratic right to be able to demonstrate anywhere and go anywhere and express the feelings that we want to in the way that we want to," said a spokesman for the D14 anti-capitalist group.
Some protest groups are keen to avoid the clashes which they feel damaged the anti-globalisation movement's reputation and prevented them from getting their message across.
"We don't want any fights with the police because that would play into their hands and put pressure on the movement," said Els Deschoemacker from the International Resistance group.
Demonstrations are expected to focus on opposition to the war in Afghanistan as well as concern that the EU's proposed anti-terrorism measures could infringe civil liberties.
Endnote: BBC TV news estimated the crowd-size at 80,000.