France is preparing for a second day of travel cancellations and school closures as unions warned there would be no let-up in the strike called to protest planned pension reforms.

The first day of a strike, seen as a major test for President Emmanuel Macron's ambitious vision of reforming France, saw giant rallies across the country coupled with walkouts that paralysed transport and closed schools.

Today appears set to follow a similar pattern, with almost all high-speed train services cancelled, most of the Paris metro system shut down and hundreds of flights set to be cancelled.

Yves Veyrier, head of the hardline FO union, warned the strike could last at least until Monday if the government did not take the right action.

"The strike is not going to stop," added Philippe Martinez, secretary general of the CGT union, late yesterday.

But it remains far from certain the protests will match the magnitude of the 1995 strikes when France was paralysed for three weeks from November to December in an action that forced the then government into concessions.

About 65,000 people walked between the Gare de l'Est and Place de la Nation in Paris

National train operator SNCF has axed 90% of the high-speed TGVs today while just 30% of regional trains will run.

On the Paris metro, ten lines will remain totally shut, four will work at a much reduced capacity and only two  driverless will work normally.

Flag carrier Air France is again axing 30% of domestic flights. There will also be severe disruptions on the Eurostar, with some two dozen trains cancelled on the cross-Channel route.

A weekend of travel misery is also expected.

National newspapers were unable to publish their print editions, and the CGT union said workers had blocked seven of the country's eight oil refineries, raising the prospect of fuel shortages if the strike continues.

Bike paths were packed as commuters turned to bicycles and electric scooters while ride-hailing companies were offering special strike promotions.

President Macron's government has yet to set out its plans in full but is pushing for a single pension scheme which critics say would require everyone to work longer.

A pre-school teacher demonstrating in the eastern city of Belfort, Anne Audier-L'Epingle, said she was striking because "I don't know what I will be able to offer two-year-old children when I'm 65".

The minimum pension age in France is 62, one of the lowest among developed countries.

But railway workers, opera employees and a host of other workers have more advantageous schemes, with train drivers for example generally retiring in their early 50s.

Police fired teargas to disperse small groups of rioters in Paris as well as in the southeastern city of Lyon and western city of Nantes.

But the dozens of demonstrations held nationwide were mainly peaceful.

More than half a million people protested across France, according to a tally of official figures, even excluding a protest that unions said gathered around a quarter of a million in Paris.

The president has faced a wave of opposition this year, from the "yellow vest" movement demanding improved living standards to more recent protests from police, firefighters, teachers, hospital workers and lawyers.

So far the former investment banker has largely succeeded in pushing through a series of controversial reforms, including loosening labour laws and tightening access to unemployment benefits.

But this is the first time the various disgruntled groups have come together in protest.

President Macron has sought to rise above the strikes and has chosen to make no official comment in the days leading up to the stoppages.

A presidential official, who asked not to be named, said he was "calm" and "determined to carry out this reform" in a mood of "listening and consultation".