Police said hundreds of activists attacked officers on Sunday ahead of a peaceful rally to protest the forced closure of an anti-capitalist camp in western France.
A week of clashes erupted on Monday when police launched an eviction operation at Notre-Dames-des-Landes camp, near the city of Nantes, set up 10 years ago to fight plans for a new airport.
Officers were attacked by around 300 protestors, some armed with molotov cocktails, who attempted to gain access to rebuild squats at the camp on Sunday morning, police said.
Two people were arrested and one officer was wounded.
Around 3,000 to 4,000 people later flocked to the site to take part in a peaceful rally defending the camp, police added.
General Richard Lizurey, director general of the French Gendarmerie, said the operation to clear the camp had been undermined by the presence of "the far-left" including "black bloc" protesters, the black-clad demonstrators who often clash with police at demonstrations around the world.
A similar rally on Saturday, attended by around 6,700 people, spilled on to the streets of Nantes where windows were broken, police said.
About 2,500 officers have been deployed to the site and 29 squats destroyed since Monday.
Many protesters have been equipped with gas masks, molotov cocktails, makeshift shields and racquets they used to knock back police tear gas cannisters during days of clashes.
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Dominique Fresneau, co-president of Acipa, the protest movement, called for calm on both sides, adding that violence delays talks.
According to a medical team set up at the activists' camp, at least 148 protesters have been injured since Monday.
Activists opposed to plans to build a new airport near the city of Nantes first began squatting on the farmland in 2008, and the camp grew into a sprawling 1,600-hectare (4,000-acre) settlement billed as a utopian leftist farming community.
But the government announced in January that it was calling off plans for the airport and warned the squatters that they must clear off the land by spring.
The week-long battle echoes a failed attempt to clear the camp in 2012.
The activists are furious at police damage to their shelters and farming projects including a sheep shed and cheese-making area, saying they had been in talks with local officials on maintaining many of the projects.
The government had said activists could stay on the land if they came up with individual farming schemes but most refused, saying they want to run the site collectively and be able to pursue non-agricultural projects.
Local authorities say 16 of the encampments dotting the farmland were cleared in the first two days of the operation, 15 of them demolished.
The plan is to dismantle up to 40 as authorities seek to retake control of a key road running through the area that has been blocked for five years.
© 2018 AFP