Riot police armed with shields and batons charged hundreds of protesting fishermen outside European Union headquarters Wednesday after a demonstration over high fuel prices turned violent.

Protesters hurled flares, firecrackers and rocks at police beyond razor-wire barricades. They also fired flare guns at the EU headquarters building and broke windows of other EU buildings. The crowd overturned at least one car and set trash cans on fire.

The police responded by firing water cannons, and about 200 officers charged to disperse the protesters.

About 400 protesting fishermen from France, Italy, Spain and Portugal besieged the EU's landmark Berlaymont headquarters for several hours before the violence broke out. They blocked the main boulevard through Brussels' European Union quarter, causing widespread traffic disruption.

Fishermen, truck drivers and farmers across Europe have protested in recent weeks to demand government aid to help compensate for high fuel costs, which they say are threatening their livelihoods.

Europeans are faced with higher fuel prices than elsewhere because of excise taxes that are added to national sales tax. EU leaders have put the problem on top of their June 19-20 summit agenda.

A delegation of fishermen met briefly outside the European Commission Wednesday with senior EU officials to outline their plight and demand emergency aid.

"To have a sustainable fishery we need to have cheaper fuel prices," said Pierre D'Acunto, a fishermen representative from the southern French port town of Sete on the Mediterranean coast. "It's impossible to work with these prices."

Patrick Tabone, a senior official from the office of EU Fisheries Commissioner Joe Borg, offered no immediate aid to the protesters. He recommended the fishermen accept calls for a mass overhaul of Europe's fisheries sector, including cutting back the size of fleets to prevent overfishing and to cut costs.

"There is a problem of high costs at the time when the sector is also in a situation where there is overcapacity and where there is a need for restructuring," Tabone told the fishermen. "What we need to ensure is that the responses we come up with are a real help to the sector, not only in the short term, but in the long term."

D'Acunto said European fishermen would continue their protests across Europe and picket EU agriculture and fisheries ministers talks planned for Luxembourg later this month.

Under pressure at home from truckers and fishermen, French Finance Minister Christine Lagarde on Monday asked EU nations to slash sales tax on fuel.

Other EU nations are skeptical of the French plan, saying it does nothing to encourage people to consume less energy in the long term or to push producers to pump more oil.