"We're here to fight for our rights," says Alissa, a student in Marseille.
She tells the BBC News Channel that they are protesting alongside teachers from their school: "We just want better conditions. They never listen to us... and if we don't fight, nobody is going to fight for us."
In Lille, thousands of people - many of them teenagers - have arrived at Place de la République, which is supposed to be the end point of this protest march.
A brass band has just started up and is pumping music out across the street. There are dozens of police officers in riot gear at the corners of the square, some of them standing in front of the government building of the Lille Préfecture.
"Everyone hates the police" is the chant that one large group of children are joining in.
Along the route, some protesters told us how they feared officers would be violent towards them today.
When I later pointed out lots of teachers and emergency service workers have also been injured over the past week or so, the response is that only a tiny minority of those protesting have been violent.
There is chanting and clapping. A red haze of smoke has drifted across one of the entry points from which hundreds more students continue to arrive.
Some young people are dressed in black with their faces covered. It’s noisy and animated but there are no obvious signs there will be disorder.
"Most of us aren't violent," she says, adding that "police they don't even let us [protesters] walk" in the street, which "creates a lot of tension in the country, in the city".
Her friend Sacha adds that there are leaks in school ceilings and in "general the condition in which we work is very poor, so we can't really work a lot of time".
"We will keep doing this until good measures are taken," he says.The union for secondary school students, which is one of the major organisers of the protest, says 2,000 high schools have shut across the country.
The Union Syndicale Lycéenne (USL) also says it has "mobilised" all universities across the country.
The union's figures on school closures differ from those given by the education ministry - which earlier said that 891 schools have had classes suspended, either totally or partially.
Media reported earlier that an estimated 86,000 protesters were demonstrating in areas outside the Paris region, according to France's interior ministry, which has been providing separate figures.
The wave of student protests that has swept France continues. People are rallying for better conditions in schools - pointing to teacher shortages, overcrowding, and dilapidated buildings.
With France's largest union turning out today, the movement shows no sign of abating - here's what is happening.
Today's demonstrations have been dubbed "Act Three" by the school movement, with parents, university students, and the Confédération Générale du Travail (CGT) - France's largest union - taking part
Hundreds of schools have been fully or partially closed - although the figures being given vary. France's education ministry says almost 900 schools have suspended classes, while the national students' union reports that 2,000 secondary schools are closed
While many are protesting peacefully, there has been disorder - including in Lyon, where barricades have been set on fire, and in Strasbourg, where there were clashes with police
Human rights organisations have expressed "serious concern" about the "disproportionate police response" to the protesters
"I am very scared for the future," one Parisian student tells the BBC. Another says that "we still feel like we are not being heard"