Paris police fired water cannon and tear gas to push back "yellow vest" demonstrators from around the Arc de Triomphe monument today, in the ninth straight weekend of protests against French President Emmanuel Macron's economic reforms.

Thousands of protesters in Paris marched noisily but mostly peacefully through the Grands Boulevards shopping area in northern Paris, close to where a massive gas explosion in a bakery killed three people earlier today.

But small groups of demonstrators broke away from the designated route and threw bottles and other projectiles at the police.

Around the Arc de Triomphe at the top of the Champs Elysees boulevard, riot police fired water cannon and tear gas at militant protesters after being pelted with stones and paint, witnesses said.

Groups of protesters also gathered on and around the Champs Elysees, the scene of disturbances in recent weeks, many of them calling loudly for Mr Macron to resign.

"Macron, we are going to tear down your place!" one banner read.

The French Interior Ministry estimated that there were a maximum of about 84,000 demonstrators nationwide today - more than the 50,000 counted last week but well below the record 282,000 estimated on 17 November, the first day of the protests.

In Paris, the ministry counted 8,000 demonstrators, more than in the past two weekends, when authorities tallied just 3,500 people on 5 January and only 800 on 29 December.

Much of central Paris was in lockdown on the first week of post-Christmas sales, with bridges across the Seine river closed and official buildings such as parliament and the Elysee presidential palace protected by police barriers.

In Paris, 156 "gilets jaunes" (yellow vest) protesters were arrested, some for carrying objects that could be used as weapons, police said.

By nightfall, there had been no looting or burning of cars as seen in previous weeks and traffic circulation had resumed around the Arc de Triomphe area.

There were also thousands of marchers in the cities of Bordeaux and Toulon in southern France as well as Strasbourg in the east and the central city of Bourges.

Bourges authorities said nearly 5,000 yellow vests stuck to the designated demonstration area. The historical city centre was off-limits for demonstrators, but some 500 protesters made their way to the centre where they scuffled with police and set rubbish bins on fire.

Many businesses in Bourges had boarded themselves up to avoid damage and authorities had removed street furniture and building site materials that could be used for barricades.

In Strasbourg, up to 2,000 demonstrators gathered in front of the European Parliament building and later marched to the centre of the city on the Rhine river border with Germany. No serious violence or looting was reported there.

More than 80,000 police were on duty for the protests nationwide, including 5,000 in Paris.