Rubbish bins set alight, projectiles hurled at police as French protest against President Emmanuel Macron's pension bill intensifies

 Black-clad groups set fire to garbage cans and threw projectiles at police in Paris who responded with teargas, on the fringes of a march against President Emmanuel Macron and his deeply unpopular pension bill.

Clashes also erupted in similar rallies in cities including Rennes, Bordeaux and Toulouse, with a bank branch and cars set ablaze in Nantes.

However, while public frustration has evolved into broader anti-Macron sentiment, the level of violence on Tuesday was nowhere near that seen last week and rallies were otherwise largely peaceful.

Earlier in the day, the government rejected a new demand by unions to suspend and rethink the pension bill, which will delay retirement age by two years to 64, infuriating labour leaders who said the government must find a way out of the crisis.

The government said it was more than willing to talk to unions, but on other topics, and repeated it would stand firm on the pension front.

Millions of people have been demonstrating and joining strike action since mid-January to show their opposition to the bill.

The protests have intensified since the government used special powers to push the bill through parliament without a vote.

Police said 93,000 people marched in Paris on Tuesday, fewer than the record 119,000 at the demonstration on March 23, but more than or equal to earlier demonstrations since January.

One protester in Paris captured the mood, brandishing a banner that read: "France is angry".

"The (pension) bill has acted as a catalyst for anger over Macron's policies," 31-year-old Fanny Charier, who works for the Pole Emploi office for job seekers, said at the same rally.

Macron, who promised to deliver pension reform in both of his presidential campaigns, says change is needed to keep the country's finances in balance. Unions and opposition parties say there are other ways to do that.

"We have proposed a way out ... and it's intolerable that we are being stonewalled again," the head of the CFDT union, Laurent Berger, told reporters at the start of a rally in Paris.