Anti-government protesters have faced off with French riot police in Paris, hurling projectiles, torching cars and vandalising shops and restaurants in a fourth weekend of unrest that has shaken President Emmanuel Macron's authority.

Police used tear gas, water cannon and horses on Saturday to charge protesters on roads fanning out from the Champs Elysees boulevard, but encountered less violence than a week ago, when the capital witnessed its worst unrest since the 1968 student riots.

As night fell and many demonstrators started returning home, Interior Minister Christophe Castaner said there had been about 10,000 protesters in Paris by early evening and some 125,000 across the country.

Security forces have arrested 1385 people across France and 985 of them have been held for questioning, Interior Minister Christophe Castaner said.

Last week, when there was more violence, authorities estimated 136,000 protesters nationwide and 5500 in Paris.

Castaner said that 118 protesters had been injured, mainly in road accidents, along with 17 members of the security forces, compared with 220 protesters and 284 members of the security forces last Saturday.

"A stop has been put to the escalation of violence," the minister said. "It nevertheless remains at a level that, although contained, is totally unacceptable."

There was less violence than last week, when rioters torched 112 cars and looted shops in the worst rioting in Paris since May 1968.

"We were on our knees and they shot tear gas at us. I am telling you, things are going to blow up tonight," said Yanis Areg, 21, from Paris.

A police source told Reuters he feared that things would get out of hand after nightfall.

Named after the fluorescent safety vests that French motorists must carry, the "yellow vest" protests erupted out of nowhere on November 17, when nearly 300,000 demonstrators nationwide took to the streets to denounce high living costs and Macron's liberal economic reforms.

Demonstrators say the reforms favour the wealthy and do nothing to help the poor and billed Saturday's protest "Act IV" of their protest after three consecutive Saturdays of rioting.

Prime Minister Edouard Philippe appealed for restraint.

"We will do all we can so that today can be a day without violence, so that the dialogue that we started this week can continue in the best possible circumstances," he said on French television.

On Tuesday, Philippe announced the government would suspend planned fuel tax increases for at least six months to help defuse weeks of protests.

The announcement marked the first U-turn by Macron's government since he came to power 18 months ago.