Some 25,000 protesters from Belgian trade unions staged a march in Brussels Friday, according to police estimates, in one of the largest anti-austerity protests in the capital of the European Union. Protest organizers said as many as 40,000 showed up.

Riot police met the demonstrators at the heart of the so-called European Quarter, on Schuman Square where EU institutions are housed, leading to outbreaks of violence and major traffic disruptions around the city.

The protesters were largely peaceful, with members making speeches on platforms as workers drank beer and chanted slogans.

They were protesting austerity in the EU and what they see as a move by governments across the bloc to signigicantly cut workers' salaries and benefits in an attempt to reduce labor costs and increase competitiveness.

"No to the Austerity-Competitiveness Pact," one big banner read.