Police in Paris have fired tear gas and used water cannon against protesters on the Champs Elysées, in the center of the French capital.
The "yellow vest" protests, which began as a campaign against rising gas prices, have morphed into a wider demonstration against the government of President Emmanuel Macron in recent weeks.
Police say they have mobilized 3,000 officers in Paris to contain the 8,000 protesters. A security perimeter has been set up in the city center, with government buildings protected. Three people have been arrested so far.
At a news conference on Saturday, French Interior Minister Christophe Castaner blamed the clashes on far-right extremists infiltrating the demonstrations.
"Today, the far right has mobilized," he told reporters. "The security forces perfectly anticipated this situation."
Far-right political leader Marine Le Pen rejected the accusations, describing it as a "pathetic and dishonest" form of "political manipulation" by the government.
Earlier Castaner said of the protesters: "Their freedom of expression will be guaranteed, but it must not be exercised to the detriment of security, public order and the right of everybody to come and go. There is no liberty without public order."
Last weekend a protester was accidentally run over and killed by a car, and more than 200 people were injured during a demonstration in eastern France.
Macron under fire
In addition to concerns over spiraling fuel prices, the protests also reflect long-running tensions between the metropolitan elite and rural poor.
Diesel prices have surged 16% this year from an average 1.24 euros ($1.41) per liter to 1.48 euros ($1.69), even hitting 1.53 euros in October, according to UFIP, France's oil industry federation.
The price hike is largely caused by a leap in the wholesale price of oil, with Brent crude oil -- a benchmark for worldwide oil purchases -- increasing by more than 20% in the first half of 2018 from around $60 a barrel to a peak of $86.07 in early October.
French protesters are, however, not directing their anger at OPEC for reducing oil production, or at the US administration for implementing tariffs on Iran, crippling its oil exports.
Macron is instead bearing the brunt of widespread French discontent, with many protesters furious at the current leader's extension of environmental policies implemented under François Hollande's government.
Notably, taxes were increased by 8 centimes last January on diesel, and by 4 centimes on petrol. Tax on diesel will also increase by another 6.4 euro cents in 2019, and by 2.9 cents for petrol. These rises follow many decades of under-taxation of diesel in France.
The growing resentment has also been a springboard for partisan political attacks, with opponents of Macron's centrist En Marche party attempting to energize their bases to fuel further revolt.
"This government hasn't understood the anger of the French," Olivier Faure, head of the French Socialist Party, said this month.
"Macron has not heard the French," Laurent Wauquiez, leader of the center-right party Les Républicains, added in an interview for BFMTV and RMC radio.
Meanwhile, Macron's former nemesis, Marine Le Pen, leader of France's far-right National Rally, said: "We were the first party to express our total support for this movement."
Castaner hit back at Macron's opponents, branding the protests "political" and accusing Les Républicains of being behind them.
"It's a political protest with the Republicans behind it, and it's irrational because the rising taxes have been compensated by the decline in the oil market," he told CNN's French affiliate BFMTV. "We hear the protests, we hear the anger, I know the situation, but we have to explain that it's essential that we exit fossil fuels."