The French government says it fears "major violence" in Paris on Saturday as the national "yellow vests" protest movement shows little sign of easing.
The government said it was scrapping the fuel tax increases in its budget - the original spark for the protests.
But broader discontent with the government has spread, and protests have erupted over several other issues.
On Thursday young people took to the streets, protesting over educational reforms.
More than 140 people were arrested when a protest outside a school in Mantes-la-Jolie in Yvelines ended in clashes with police. Dozens of other schools were blockaded in cities including Marseille, Nantes and Paris.
Students have been angered by President Emmanuel Macron's plans to change the end-of-school exam, known as the baccalaureate, which is required for entrance to university. Critics fear the reforms will limit opportunity and breed inequality.
Meanwhile, Saturday's planned rally of the yellow vests looks set to go ahead. Recent protests have turned violent, causing millions of euros in damage.
Police have advised shops and restaurants on the Champs-Elysees to shut for the day. Some museums in Paris have also said they will be closed.
Prime Minister Édouard Philippe told the Senate that "exceptional means" would be used on Saturday in addition to 65,000 police officers on duty across France.
Confirming that the fuel tax had been abandoned, he told senators that the calm of most protesters around the country contrasted with the "extreme violence" seen in Paris.
"Unlike others, I'm not seeking to apportion blame for this anger," he said. As mayor of the northern port of Le Havre he said he had felt local anger rise every year, after every election. "It's been muted for a long time, because it's been silenced for a long time, by shame, sometimes by pride."
According to French media, Mr Philippe will decide on Saturday whether to deploy armoured vehicles to clear roads in Paris if barricades are erected. Such a deployment has not taken place since 1968.
The protest on Saturday 1 December descended into the worst rioting seen in decades, with hundreds of injuries and arrests.
The government says extremists hijacked the protests and incited violence.
French health minister Agnès Buzyn, speaking to RTL Radio on Thursday morning, said: "There is a concern about this violence, and some who do not want to find a solution."
The government is considering mobilising the military to protect important national monuments, French broadcaster BFMTV reported, after the world-famous Arc de Triomphe was damaged last week.
A series of football matches have also been postponed. They include those between Paris and Montpellier, Monaco and Nice, Toulouse and Lyon, and Saint-Etienne and Marseille.
The yellow vests protests have moved beyond the initial anger over fuel taxes. Last week, the movement - despite a lack of central leadership - issued more than 40 demands to government.
Among them were a minimum pension, widespread changes to the tax system, and a reduction in the retirement age.
The government has already acknowledged some of the concerns, suggesting it may review the "wealth tax" it abolished after taking power.
An analysis of its original budget plans for 2018-2019 showed it benefitted the very wealthy rather than the very poor.
Other groups, bolstered by the success of the national movement, have also begun separate actions.
One police union, Vigi, called for a strike of its administrative staff working in the interior ministry for Saturday - saying that without the support of such staff, riot police would be immobilised.
Two road transport unions, the CGT and FO, have called for a strike among its 700,000 members on Sunday, Le Monde reported. Drivers have been affected by changes to overtime payments, the unions say, which affect the purchasing power of its members.