Hundreds of thousands of strikers paralyzed the transport system on the first day of industrial action which prompted the closure of schools across the nation.
According to union leaders, more than 1.5 million people turned out across the country, with police using tear gas to disperse them.
Just in Paris alone, tens of thousands of people took to the streets, while more than 6,000 police officers were deployed with a decree to forbid the protesters from gathering on the Champs-Élysées or at police stations.
Police in riot gear used tear gas and truncheons to disperse protesters near the Place de la Republique. The judiciary 57 people were detained on Thursday.
Strikers on Friday were set to continue a similar pattern across the country, with widespread rail cancellations and disruption to flights expected across the nation.
In Paris, most of the metro system shut down and hundreds of flights were expected to be canceled.
Union leaders warned that the strike could last at least until Monday if the government did not take the right action.
“The strike is not going to stop tonight,” said Philippe Martinez, secretary-general of the CGT union, on Thursday.
Paris’s bus and metro operator have said their walkout will last until Monday at the very least.
President Macron is already faced with a major challenge to his rule from “Yellow Vest” protesters, who have been holding weekly demonstrations for more than a year.
Trade union leaders are now calling on Macron to abandon his campaign promise to overhaul the retirement system.
The president has said he wants to simplify the country’s complex retirement system, which comprises more than 40 different plans, many with different retirement ages and benefits.
The new system will introduce a “points system” for retirement, which will have a significant impact on the public sector.
Until now, the sector had enjoyed special retirement systems to compensate for difficult working conditions.