PARIS

A call by France’s main trade unions for a day of action in ongoing pension reform protests drew an estimated 370,000 people Thursday in Paris alone, up 20,000 from the previous mobilization on Dec. 15.

Green, purple, yellow and red flags could be seen covering the Place de la Republique brought by the Service National Universel (SNU), General Confederation of Labour (CGT) and rail operator SNCF.

Giant balloons to match bobbed in the wind, and songs of solidarity could be heard from workers from public transport operator RATP. Even the Paris Opera had a presence.

A group from the CGT played a rash of musical instruments. Everywhere, handwritten signs pronounced messages, but two words stood out: En grève -- On strike.

Workers young and old, uniformed or in plainclothes, took to the streets of the capital as well as major cities across France in protest against President Emmanuel Macron's planned overhaul of the national pension system. Estimates by the Interior Ministry put the total at 425,000 nationwide.

Strikers have for 36 days denounced the government's proposed actions, bringing chaos to the metro, rail and bus systems. Today, they were joined by teachers, lawyers, civil servants and even members of the gilets jaunes, or yellow vests protest movement, in solidarity from Brest to Nice and from Lille to Perpignan.

Macron's proposed changes focus on the consolidation of 42 different plans presently in place into one and the raising of the retirement age from 62 to 64, although workers could legally retire at 62.

Marianne Aux Enfants, a professor of history, said she was here for the next generation.

"The system is the best in the world. We have a heritage of liberation, and we must preserve it. This is important for the children and for their future."

Workers were resolute, clashing with police on the rue Châteaudun, with 16 police officers reported injured and 20 demonstrators. An insurance agency was looted and store windows were broken.

Only two out of 14 of Paris' metro lines ran all day, and RER commuter train and SNCF rail service remained limited.

Negotiations will resume tomorrow with Prime Minister Edouard Philippe.

Another day of mobilization has been called by the unions for this Saturday.