An anti-tax protest by thousands of small businessmen turned violent on Monday and left 21 people injured, police said.
Over 3,000 bakers, butchers, auto mechanics, house painters and other tradesmen rioted during a march on the local social security building, smashing ground floor windows before setting the building on fire.
The protesters burned tires and garbage cans in the streets of this southwestern French city and then threw stones and firebombs at police trying to halt the rampage.
The 21 injured included police and demonstrators. At least 80 people were arrested, police said.
The demonstrators, who came from all over western France, were protesting a tax hike and what they called unfair competition from supermarket chains.