Paris was in lockdown early on Saturday with thousands of French security forces braced to meet renewed rioting by "yellow vest" protesters in the capital and other cities in a fourth weekend of confrontation over living costs.

The Eiffel Tower and other tourist landmarks were shut, shops were boarded up to avoid looting and street furniture removed to avoid metal bars from being used as projectiles.

About 89,000 police were deployed across the country.

Of these, about 8,000 were deployed in Paris to avoid a repeat of last Saturday's mayhem when rioters torched cars and looted shops off the famed Champs Elysees boulevard, and defaced the Arc de Triomphe with graffiti directed at President Emmanuel Macron.

Protesters, using social media, have billed the weekend as "Act IV" in a dramatic challenge to Macron and his policies.

The protests, named after the high-visibility safety jackets French motorists have to keep in their cars, erupted in November over the squeeze on household budgets caused by fuel taxes.

Demonstrations have since swelled into a broad, sometimes-violent rebellion against Macron - a challenge made more difficult to handle since the movement has no formal leader.

Authorities say the protests have been hijacked by far-right and anarchist elements bent on violence and stirring up social unrest in a direct affront to Macron and the security forces.

Nonetheless, the 40-year-old Macron, whose popularity is at a low ebb according to polls, has been forced into making the first major U-turn of his presidency by abandoning a fuel tax.

Despite the climbdown, the "yellow vests" continue to demand more concessions from the government, including lower taxes, higher salaries, cheaper energy costs, better retirement provisions and even Macron's resignation.

One of them, Eric Drouet, a truck driver, called on protesters to storm into the Elysee presidential palace. An Elysee official has said intelligence suggested that some protesters would come to the capital "to vandalise and to kill".

Macron, who has not spoken in public since he condemned last Saturday's disturbances while at the G20 summit in Argentina, will address the nation early next week, his office said.

On Friday evening, he visited a group of police in their barracks outside Paris, his office said.

Navigating his biggest crisis since being elected 18 months ago, Macron has left it largely to his prime minister, Edouard Philippe, to deal in public with the turmoil and offer concessions.

But he is under pressure to speak more fully as his administration tries to regain the initiative following three weeks of unrest that are the worst since the 1968 student riots.

In a sign the concessions offered by the government may be starting to weaken support for the movement, two opinion polls showed a decline in popularity for the "yellow vests" on Friday.

The protests were supported by 66 percent of respondents in an Ifop-Fiducial poll for CNews TV, down six percentage points since a previous poll carried out on Dec. 3-4.