Adam Sage, The Times, March 9, 2017

More than 50 teenagers were under arrest yesterday after gangs of pupils, many armed with iron bars and concealing their identities beneath hoodies, went on the rampage through three schools in the crime-ridden suburbs north of Paris.

Teachers in Saint-Denis had to barricade themselves in their classrooms after protests against alleged police brutality turned violent and the pupils brought chaos to the lycées, the equivalent of sixth-form colleges.

“A dam seems to have burst with the introduction of violence inside schools,” said Najat Vallaud-Belkacem, the education minister. “These are very serious acts.”

Opposition politicians said that the rioting was evidence that lawlessness was gaining ground in the suburbs of big cities against a backdrop of ethnic and religious tensions that have plagued France in recent years.

Marine Le Pen, leader of the far-right National Front, condemned the “stupefying” level of unrest. “It is not tolerable that hoodlums threaten the future of our country and put teachers and pupils in danger,” she said.

She accused the Socialist government of a “minimal reaction” and called for a zero-tolerance policy on crime.

Police arrested some of the pupils involved after ordering the evacuation of Lycée Suger

However, Bernard Cazeneuve, the prime minister, accused Ms Le Pen of seeking to “provoke and stoke disorder” and of seizing the opportunity to win votes in the first round of the presidential election next month. “This is not a service to our country,” he said.

Philippe Tournier, general-secretary of the head teachers’ union, said that it was the first time that French schools had come under attack in that way. The incident illustrated the mounting tensions in the ethnic tinderboxes that are suburban council estates across the country, he added. “We have reached a new level of violence,” he said. “If things carry on this way it will end up [with someone dying].”

The riots followed widespread calls on social media to demonstrate outside lycées in Saint-Denis over alleged police violence — including the case of a young black man, Théo Luhaka, 22, from Aulnay-sous-Bois, who was allegedly beaten and sexually assaulted while being arrested by several white police officers on February 2. The incident led to widespread disturbances last month, with protesters clashing with police and blocking numerous schools in and around Paris.

On Tuesday most of the demonstrators tried only to stop pupils attending lessons, but the Lycée Suger in Saint-Denis was ransacked by about a hundred pupils.

Staff said that the teenagers had set fire to bins and furniture and had lit smoke bombs and explosive devices. One doused a stairway in petrol before setting it ablaze. The fire was put out by a teacher using an extinguisher.

At one point a paving stone was thrown through a staff room window as several teachers cowered inside.

“We were really scared. I have never seen such a level of aggression,” a teacher who declined to be named said. “There were small groups moving around the school and trying to set fire to different places. It was quite difficult to contain them.”

Police ordered the evacuation of Lycée Suger after arriving at the scene. That led to clashes between pupils and officers outside the establishment.

A group of 80 protesters then swarmed towards the centre of Saint-Denis, attacking two other lycées on the way. Witnesses said they forced pupils in the schools to leave their classrooms, threatening them with iron bars. The riot ended with more clashes between pupils and police, with officers coming under a hail of paving stones and rocks.

Fifty-four people were arrested, most of them pupils at Lycée Suger. All but ten were younger than 18 and the youngest was 15. Most were released without charge last night. Eight minors were due before a juvenile court judge today on charges of violence, “armed gathering” and “rebellion”. Prosecutors said that their detention would be extended for 24 hours while officers tried to determine their roles in the riot.

Many texted their parents to say that they would not be coming home because they were in custody. “My daughter is 17 and she has never been in trouble before in her life,” the mother of one of the pupils said. “The first I knew about this was when she sent me a text message to say she was in the police station. She hasn’t even been able to have a shower.”

Rodrigo Arenas, chairman of the local parent-teacher association, said that there was enormous tension in Parisian suburbs after the alleged assault on Mr Luhaka. Many of the protesters this week chanted “Revenge for Théo”.

He said that youths felt excluded by mainstream French society and regarded schools as “representations” of a state that discriminated against them. “The only way many of them can express themselves is through violence,” he said.

In October a female headteacher was punched in the face after trying to stop youths throwing a petrol bomb at her school in Tremblay-en-France, near Saint-Denis. She had earlier asked police to end drug trafficking on the pavement outside the school. Last week another headteacher was injured when a fire extinguisher was thrown at him during a protest outside his lycée.

Emmanuel Macron has overtaken Marine Le Pen for the first time since announcing he was running for president. A poll by Harris Interactive poll shows Mr Macron in first place on 26 per cent, one point ahead of Ms Le Pen, who has been leading for some time.

The poll shows that Mr Macron would be a clear winner in the event of a run-off following the first-round vote on April 23.

His movement, En Marche!, has won the support of the centre left and centre right as scandal engulfs the Republican candidate François Fillon and President Hollande’s Socialists plummet in popularity.