A protester with trauma to the head was fighting for his life on Sunday following clashes with police during a demonstration over water storage facilities in France, a prosecutor said.
The 30-year-old man was among three protesters admitted for emergency treatment after the protest in the southwestern village of Sainte-Soline Saturday, prosecutor Julien Wattebled said.
The other two were a 19-year-old woman with a facial injury and a 27-year-old man with a broken foot.
A special inquiry had been opened "to determine the exact nature" of their injuries and "the circumstances" leading to them, Wattebled said.
Four more protesters were injured but not hospitalized, while 29 police officers also sustained injuries, two of whom had to be taken to hospital, the prosecutor's office said.
Protesters in Sainte-Soline were trying to stop the construction of giant water "basins" to irrigate crops, which they say will distort access to water amid drought conditions.
The water reserve is the second of 16 such installations, part of a project developed by a group of 400 farmers to significantly reduce main water usage in summer.
The open-air craters, covered with a plastic tarpaulin, are filled by pumping water from surface groundwater in winter and can store up to 140 million gallons of water.
This water is used for irrigation in summer, when rainfall is scarcer.
Opponents claim the "megabasins" are wrongly reserved for large export-oriented grain farms and deprive the community of access to the essential resource.
The authorities said 6,000 protesters took part, while organiszrs said there were up to 30,000 people.
Once they arrived at the construction site, which was defended by around 3,000 members of the security forces, clashes quickly broke out between the more radical activists and police, AFP correspondents said.
Protesters threw projectiles including improvised explosives, while police responded with tear gas, water cannons, and rubber bullets.
'Indiscriminate Use of Force'
The French government denounced "an intolerable surge of violence," while organizers condemned "a massive repression operation."
"I can only condemn the extreme violence," Prime Minister Elisabeth Borne told AFP on Sunday, referring to "images of individuals who have no other objective than to injure the police."
The Human Rights League, a French watchdog, on Sunday accused the police of resorting to "unrestrained and indiscriminate use of force on all people present."
Its 22 observers on site recorded "massive and indiscriminate firing of tear gas" by police at the crowds, it added.
This included tear gas fired at elected officials protecting injured people and "several cases of the force impeding the intervention of rescue services," it said.
The police responded that its members had faced "extremely violent individuals" and had applied "proportionate use of force, massively using tear gas."
Officers had not seen any officials, and were "attacked by people armed with incendiary devices" as the injured were to be evacuated, police added.
The clashes in Sainte-Soline came after days of unrest elsewhere in France over President Emmanuel Macron's pensions reform, which forced the cancellation of a visit by Britain's King Charles III.
Outrage over Macron imposing the bill without a parliamentary vote has sparked daily clashes between protesters and police in French cities over the past week.
But since January, hundreds of thousands of French people have also peacefully marched against the reform, which includes raising the retirement age from 62 to 64.
Security forces have this week faced criticism for their heavy-handed tactics in dealing with the protests.
On Friday, the Council of Europe warned that sporadic violence in protests "cannot justify excessive use of force."