Hundreds of high school students have barricaded school entrances across Paris demonstrating against alleged police brutality, as a major labour union of police officers staged its own rally to demand more personnel and equipment.

The separate demonstrations on Thursday came three weeks after a young environmentalist died during a protest in southern France in which several hundred activists opposed to a dam project clashed with police.

An investigation is continuing into the death of Remi Fraisse, but an autopsy found a large wound on his back was caused by some kind of explosion.

Students stacked garbage bins in front of doors at several Paris high schools, as about 150 students marched from the Place de la Nation.

"We are fed up of discrimination, flash balls or grenades. We are fed up," Stan Ferjus, a member of the high school students' union, told the Associated Press.

Another high school student, Mohammed Auas, said: "Police forces are here to protect us. Police forces are here to guarantee our security. If they don't guarantee it, who will protect us? They shouldn't be violent to us. They can do their job, but they shouldn't be violent."

Meanwhile, the Alliance police union was holding its own demonstration at nearby Place de la Bastille, where several thousand protesters gathered.

They were demanding more equipment and personnel so they can do their jobs safely.

Source: Associated Press