One police officer and a protester were seriously injured on Saturday in clashes during an unauthorised demonstration against the construction of a water reservoir for farm irrigation in western France.
Police fired tear gas to repel some protesters who threw fireworks and other projectiles as they crossed fields to approach the construction area in the rural district of Sainte-Soline. At least three police vehicles were set alight, television footage showed.
Emmanuelle Dubee, the prefect of the surrounding region, said at least 6,000 protesters had joined the march, defying a ban on protests at the site where a similar protest last October also turned violent.
One officer and one protestor were in a critical condition, Interior Minister Gerald Darmanin said, adding their lives were not in danger.
In all, seven protesters and 24 police officers were injured, said Darmanin, who blamed the violence on around 1,000 far-left activists. Disturbances had started in nearby areas on Friday ahead of Saturday's violence, with police detaining 12 people, he added.
Around 3,200 police officers, some in helicopters and on quad bikes, were deployed for the demonstration, the authorities said. Stun grenades were used to repel protesters, Darmanin said.
The protest over the irrigation project comes after weeks of demonstrations in France against a pension reform that have turned violent since the government pushed through the legislation without a final parliamentary vote.
France's worst drought on record last summer sharpened the debate over water resources in the European Union's biggest agricultural sector.
Supporters say artificial reservoirs are a way to use water efficiently when needed, while critics - who call them "mega-basins" - argue they are outsized and favour large farms.
(Reporting by Yves Herman and Marco Trujillo; additional reporting and writing by Gus Trompiz; Editing by Mike Harrison)