France's Yellow Vest protesters were back on the streets for the eighth consecutive weekend in cities across the country.
Up to 4,000 people joined the protest at its height in Paris on Saturday as French security forces deployed tear gas and protesters lit fires.
Police boats patrolled the river while beyond the Seine, motorcycles and a car were set on fire on the Boulevard Saint Germain, a main Left Bank thoroughfare.
Riot police and firefighters moved in, and barricades mounted in the middle of the wide street also glowed in orange flames.
The march on the eighth consecutive Saturday of yellow vest protests had been declared in advance and approved, in contrast to some illegal December demonstrations that degenerated into vandalism, looting and chaos.
The atmosphere mostly was calm, but turned when some protesters tried to cross the river on a pedestrian bridge not on the official route from City Hall to the National Assembly, the lower house of parliament.
Police used clubs and tear gas, then held the bridge in a standoff while violence broke out.
Some confrontations between police and protesters took place in other cities around France, with tear gas fired in Bordeaux in the southwest and in Rouen in Normandy.
Demonstrations continued on Sunday when several hundred female members of the movement held their own protest at the Bastille monument.