As the French 'yellow vest' movement continued on Saturday, with 50,000 protesters marching through Paris and across France according to the French government, president Emmanuel Macron has denounced the "extreme violence" of some clashes that erupted at the Paris march.

These new protests follow Macron's government announcing on Friday that it would harden its stance against the 'yellow vests'.

For the past two months, the 'yellow vests' or 'gilets jaunes' have been blocking roads, occupying highway toll-booths and organising weekly, sometimes violent, marches in Paris. Driving the movement is the feeling among French workers and lower-middle class that they cannot make ends meet, and anger at Macron's reforms seen as favouring the rich.

'Yellow vest' protesters gathered in Paris on Saturday afternoon, chanting the French national anthem 'La Marseillaise' and waving anti-Macron banners. They were about 4,000, according to the police.

They peacefully marched from the Champs-Elysees boulevard through central Paris, gathering at the stock exchange to call for Emmanuel Macron's resignation. Shops and restaurants remained open, although the Galeries Lafayette department store briefly shut its doors.

The protests turned violent as the march entered the city centre. Protesters threw bottles and rocks at the police, who responded with tear gas. Police officers were beaten up during clashes on the Léopold-Sédar-Senghor bridge near the National Assembly. One was injured, AFP reported. Police cars were attacked on Rue de Rivoli, by the Louvre museum. Cars and barricades were set ablaze on the boulevard Saint-Germain, a famed and wealthy Parisian area.

After the French government's spokesperson, Benjamin Griveaux, was escorted from his office as 'yellow vests' managed to enter his ministry's courtyard, president Macron denounced an "extreme violence" that came to "attack the Republic".

"We will be protesting here every Saturday, it will go on for all of 2019", a protester named Sophie declared in a megaphone on the Champs-Elysees, AFP reported. "We will make sure that citizens take back power."

"They have no right to leave us in the shit like this," Paris protester Francois Cordier told Reuters. "We're fed up with having to pay out the whole time, we've had enough of this slavery, we should be able to live on our salaries."

Interior minister Christophe Castaner condemned Saturday's violent events in Paris and called for "responsibility and respect of the law".

Thousands more gathered in other French cities. In Bordeaux in the southwest, they were 4,600 according to local authorities. They were 2,000 in Rouen and more than 1,000 in Lille, in the north, and 2,000 in Nantes, in the west. Marches were also held in Rennes, in the west, and Lyon and Marseille in the southeast. In Lyon, 'yellow vests' blocked the A7 motorway.

Taken by surprise by the 'yellow vest' protests at the end of last year, Macron's government started 2019 on the offensive, calling the remaining protesters "agitators" seeking to overthrow the government. On Wednesday night, one of the prominent figures of the 'yellow vests' was arrested by the police.

On Friday, the French government promised it would "go on with the changes" it is introducing in France and would be "more radical" in doing so.

The 'yellow vest' movement spread to London on Saturday, where about 100 people marched on Parliament Square and Whitehall white wearing the symbolic neon yellow