Police firing tear gas and using water cannon clashed with protesters in Paris who are angry over rising fuel costs and President Emmanuel Macron's economic policies, the second weekend of "yellow vest" protests across France.
A trailer was set on fire and exploded on the Champs Elysees and a man who tried to attack fire fighters was overpowered by some of the demonstrators themselves.
On the nearby Avenue de Friedland, police fired special rubber balls to control demonstrators. At least 18 people had been detained so far, police said.
Around 5,000 protesters had converged on the Champs Elysees where police tried to to prevent them from reaching the president's Elysee Palace nearby.
Protesters sang the national anthem and waved French flags while others carried signs with slogans saying "Macron, resignation" and "Macron, thief".
Interior Minister Christophe Castaner accused far-right leader Marine Le Pen of fanning the protests.
"The ultra-right is mobilised and is building barricades on the Champs Elysees. They are progressively being neutralised and pushed back by police," he said.
In a message on Twitter, Le Pen said she had questioned why no protests were being allowed in the area.
"Today Mr Castaner is using this to target me. This is low and dishonest" she said.
Protesters are opposed to taxes Macron introduced last year on diesel and petrol which are designed to encourage people to shift to more environmentally friendly transport. Alongside the tax, the government has offered incentives to buy green or electric vehicles.
For more than a week, protesters clad in the fluorescent yellow jackets that all motorists in France must have in their cars have blocked highways across the country with burning barricades and convoys of slow-moving trucks, obstructing access to fuel depots, shopping centres and some factories.
CHALLENGE FOR MACRON
Last Saturday, when nearly 300,000 people took part in the first yellow vest demonstrations countrywide, retailers' daily revenue fell 35 percent, according to consumer groups.
By midday there were nearly 44,000 demonstrators involved in 948 protests and 516 blockades across France, a police union source said.
Demonstrators were blocking access to shopping malls in Bollene and Carpentras in Southern France while in Dole, in eastern France, a man carrying a weapon was overpowered on a roundabout occupied by demonstrators.
The unrest is a dilemma for Macron who casts himself as a champion against climate change but has been derided as out of touch with common folk and is fighting a slump in popularity.
Despite calls for calm from the government, the yellow vest protests have spread to French territories abroad, including the Indian Ocean island of Reunion, where cars were set on fire.
While the movement, which has no leader, began as a backlash against higher fuel prices, it has tapped into broader frustration at the sense of a squeeze on household spending power under Macron's 18-month-old government.
Since coming to power, Macron has seen off trade union and street demonstrations against his changes to the labour rules, and overhauled the heavily indebted state rail operator. Foreign investors have largely cheered his pro-business administration.
But political foes have dismissed him as the "president of the rich" for ending a wealth tax, and voters appear to be growing restless, with the 40-year-old president's popularity slumped at barely 20 percent.
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