Protests against the French government's pension reform on Thursday ended in Paris.
Thursday's rally was marred by acts of violence.
Angry protesters threw projectiles at police, vandalized shops and set fire, local media reported.
Some groups attacked La Rotonde restaurant, considered one of President Emmanuel Macron's favorite venues after he celebrated the first round of the 2017 presidential elections there.
Police have arrested 20 people so far, local media reported.
The Interior Ministry estimated 57,000 protesters gathered in Paris on Thursday. The General Labor Confederation (CGT) trade union said 400,000 people attended the protest.
Trade unions also set a new date of mass mobilization, for the 12th time, on April 13, daily Le Figaro said.
This was the 11th day of planned mobilization since January, with thousands of workers protesting and walking out in various sectors, including transportation, energy, and education.
Protests were held in other cities as well, including Lyon, Rennes, and Marseille.
A group of protesting railway workers entered the premises of the multinational asset management company BlackRock – the historic Centorial building, the daily added.
The group left the building shortly after and headed to Place de la Concorde square, near the National Assembly.
Pension reform plan, source of popular furor
The government revealed the reform project in January and parliament started examining and debating the draft bill the following month.
Workers and trade unions have since expressed growing outrage by holding demonstrations and walkouts against the reform which includes raising the retirement age from 62 to 64 by 2030, requiring at least 43 years of work to be eligible for a full pension.
Political and social tension rose when President Emmanuel Macron and Prime Minister Elisabeth Borne decided to use special constitutional powers – Article 49.3 – on March 16 to force the plan through without parliamentary approval.
The decision was driven by fear that lawmakers would be able to block the reforms as the government does not hold an absolute majority in the legislature.
