French police moved to dislodge protesters blocking roads and fuel depots on Tuesday as the government took a harder line on the so-called "yellow vest" movement that has sprung up in opposition to President Emmanuel Macron.

Hundreds of thousands of people blockaded roads across France on Saturday wearing high-visibility yellow vests in a national wave of defiance aimed at 40-year-old centrist Macron.

The disruption underlined the anger and frustration felt by many motorists, particularly in rural areas or small towns, who are fed up with what they see as the government's anti-car policies, including tax hikes on diesel.

Macron, who has made a point of not backing down in the face of public pressure during his time in office, on Tuesday called for more "dialogue" to better explain his policies.

Prime Minister Edouard Philippe urged ruling Republic On The Move lawmakers on Tuesday to stand firm in the face of voter criticism, saying the party would reap the rewards of its "constancy and determination".

One person was accidentally killed and 530 people have been injured, 17 seriously, over four days of protests that have come to encompass a wide variety of grievances over the rising cost of living.

Interior Minister Christophe Castaner has instructed police to begin breaking up the remaining roadblocks, particularly those around fuel depots and sites of strategic importance.

"We can see today that there are real excesses from a movement that was for the most part conducted in good spirit on Saturday," he told France 2 TV.

Several of the injuries were caused by motorists trying to force their way through roadblocks, but some protesters have also been accused of intimidating people or putting their lives in danger.

A 32-year-old man with a history of violence was given a four-month prison sentence by a Strasbourg court for endangering lives by taking part in a human chain to cross a motorway.

'Much more than fuel' 

AFP judicial sources on Tuesday however denied media reports that a group of men arrested earlier this month in the city of Saint-Etienne on suspicion of plotting an attack had planned to strike during Saturday's fuel protests.

On Tuesday, the movement appeared to be losing steam with only a fraction of the nearly 300,000 people that manned the barricades on Saturday still camped out in the cold.

Further protests are however planned at the weekend with some calling for a blockade of Paris.

The grassroots "yellow vest" movement, which has won backing from opposition parties on both the left and right as well as a majority of respondents in opinion polls, accuses Macron of squeezing the less well-off while reducing taxes for the rich.

"It's about much more than fuel. They (the government) have left us with nothing," Dominique, a 50-year-old unemployed technician told AFP at a roadblock in the town of Martigues, near the southern city of Marseille.

Macron's government, which is trying to improve its environmental credentials, has vowed not to back down on trying to wean people off their cars through fuel taxes.

The government has unveiled a 500-million-euro package of measures to help low-income households, including energy subsidies and higher scrappage bonuses for the purchase of cleaner vehicles.