Police clash with fisherman at EU in Brussels
The latest clashes follows weeks of strikes by French fishermen.
The fishermen are upset at EU policies that bans national governments from giving them more financial aid and fuel subsidies.
Several windows in EU buildings were broken and at least one car was overturned during the demonstration.
Riot police responded by firing water cannon and launching baton charges.
French fishermen have been on strike for several weeks over the price of diesel, which has risen by 240% in the past five years.
In recent days they have been joined by members of fleets from the UK, Spain, Portugal and Italy, who have blockaded ports across Europe, and truck drivers.
After several hours of stand-off, the protest turned violent. A car was overturned, bins were set on fire and windows were smashed by flares.
Riot police lined up behind a barbed-wire barricade in front of the European Commission responded by attempting to disperse the crowd with water cannons and baton charges.
Earlier, a delegation of fishermen met senior EU officials briefly outside the Commission's headquarters to explain their grievances and demand emergency aid from both the EU and their countries' governments.