Criticism from human rights watchdogs mounted on Friday over the alleged brutality of French police in handling protests opposed to President Emmanuel Macron's pension reform.
French authorities arrested more than 450 people on Thursday in the most violent day of demonstrations since the start of the year against the bill to raise the retirement age from 62 to 64.
In the days leading up to Thursday's protests, rights groups had expressed worries over what they termed "arbitrary" detentions and the excessive use of force by police.
But security officials have defended their actions, saying they are responding to violent rioters and anarchist groups who frequently infiltrate French demonstrations to provoke clashes.
France's Human Rights League has accused the authorities of "undermining the right of citizens to protest by making disproportionate and dangerous use of public force".
"The authoritarian shift of the French state, the brutalisation of social relations through its police, violence of all kinds and impunity are a major scandal," the league's president Patrick Baudouin said on Friday.
The Council of Europe -- the continent's leading human rights watchdog -- warned that sporadic acts of violence could not justify "excessive use of force by agents of the state".
Rights groups have raised concerns over the repeated use by police of "kettling", also called "trap and detain" in the United States, a crowd-control tactic consisting of cordoning off protesters in a small area.
They have sounded the alarm after reports from recent protests of police detaining foreign schoolchildren, firing teargas at kettled protesters, and even hurting a man so badly he had to have a testicle amputated.
Teenagers, jogger detained
Macron's government on Thursday last week used a controversial executive power to adopt the pensions bill without a parliamentary vote, sparking spontaneous protests in major cities.
In the days since, videos of police actions that appeared on social media appearing to show police knocking over or hitting demonstrators.
Human Rights Watch told AFP it was very concerned about "what appears to be abusive police practices".
They echoed similar "abusive crowd control and anti-riot tactics" during the anti-government "Yellow Vest" movement in 2018-2019 during Macron's previous term in office, said the group.
"The French authorities have apparently not drawn lessons from this or reviewed their police crowd control policies and practices," HRW's France director Benedicte Jeannerod said.
Critics have denounced police carrying out sweeping "preventive" detentions, saying even blameless passersby have been caught up in their dragnet.
In one instance on Thursday night last week, two 15-year-old Austrians on a school trip were among those kettled by police, Liberation newspaper reported.
The teenagers, who had been trying to find their host families, spent the night in jail before their embassy intervened.
A man out jogging was detained the same night.
He told France Inter radio he was booked on allegations ticked at random on the charge sheet, and not released until the following afternoon.
While the security forces detained 292 people that night, 283 of them were freed without charge.
'View to commit violence'
Macron on Friday condemned the overnight violence and said security forces had worked "in an exemplary manner".
Interior Minister Gerald Darmanin said the police had responded to "troublemakers, often from the far left", who had caused 441 police to be injured.
AFP saw suspected anarchists and other protesters setting fire to rubbish, smashing shop windows and launching stones and fireworks at security forces.
Darmanin said that 11 internal inquiries had been opened into alleged police brutality in the past week.
"It is possible that, individually, police, often because they are tired, commit acts inconsistent with what they were taught," he said.