452,000 protesters hit the streets in France to continue their opposition to proposed pension reforms, according to the French Ministry of the Interior.
France's CGT trade union numbers 370,000 demonstrators in Paris, and 56,000 according to the Ministry of Interior.
There were 6,000 demonstrators according to the police in Clermont-Ferrand (18,000 according to the unions), 10,000 in Bordeaux (70,000), 14,000 in Toulouse (120,000), 8,400 in Nantes (18,000), 22,000 in Marseille (220,000), 11,000 in Lyon ( 27,000).
The day of national action comes just two days after unions and the government restarted negotiations.
Towards the end of the day, police began using tear gas in the French capital as tensions heightened with demonstrators.
On social networks, numerous testimonies have reported overflowing of the police, making use of incredible violence.
Transport was again thrown into chaos on Thursday as the record-breaking social movement entered its 36th consecutive day, making it one of the longest in the country's history.
SNCF said train services were "very disrupted" with 60% of TGV, 40% of TER and a third of Transilien in circulation. Paris metro and suburban lines remain "severely disrupted", despite some "improvements" on four lines.
Flights and maritime transport could also be delayed or cancelled as unions representing air traffic controllers and port workers have joined the strike while some unions have also called for blockade operations at refineries.
As well as Paris, there were protests planned in Lyon, Toulouse, Bordeaux, Lille and Rennes and unions have already called for another day of action on Saturday, January 11.
They are protesting plans by Macron's government to overhaul the pension system by rolling the 42 different plans into a universal one.
The plans would also see pension payouts calculated from salaries from across the whole career instead of just the last five years of activity, which unions say would result in much smaller payouts.
The government also wants to phase out the early retirement advantages certain sectors — primarily in the civil service — enjoy by adjusting so-called "hardship" criterion.
Unions will be hoping for another show of force after their first mass protest on December 5 gathered 1.5 million people, according to organisers, and 800,000, according to the government.
Polls suggest however that support is slipping as the movement enters its second month. An Ifop poll released on Sunday by Le Journal du Dimanche found that only 44% of French people back the strike, down seven percentage points from the previous survey carried out before Christmas. It also found that 75% believe that President Emmanuel Macron will not cave.
Macron has so far remained steadfast in the face of discontent and vowed n his New Year's address to "carry out the reform to its end". He said abandoning the reform would be "a betrayal of our children, their children after them, who would have to pay the price for our giving up."