Police in northeast France used water cannons and fired tear gas and stun grenades Tuesday against demonstrators protesting plans to store nuclear waste at an underground site.
The issue has been raging for years as the waste is the dangerous long-term by-product of France's extensive nuclear energy program.
Around 300 protesters took part in the demonstration in Bure, a commune in the Meuse department, against plans to store highly radioactive waste 500 meters underground.
Protest organizers said 36 people were injured, with six gravely hurt in the clashes, while the local prefecture said at least three demonstrators had been injured, according to calls to emergency services.
The protest was one in a series to try to block the waste site.
France's Environment Minister Nicolas Hulot has said he needs more information before he gave his position on the project.
Earlier this month, the Nuclear Safety Authority said it had "reservations" about the project, known as Cigeo, citing uncertainty about the potential danger from highly inflammable material in the case of rising temperatures.
In July, the National Agency for the Management of Radioactive Waste said construction of the storage site would start in 2022 at the earliest.