Thousands of people demonstrated on Saturday against French President Emmanuel Macron's proposed pension reforms which have sparked a month-long transport strike.
Some protesters donned the yellow vests which over the past year have become symbolic of opposition to Macron's attempts at reforms he says will rationalise France's 42 separate pension regimes into a single points-based system.
Unions reject the scheme saying it would require millions of people to work beyond the official retirement age of 62.
The marchers set off after midday from the Gare de Lyon railway station in eastern Paris behind a giant banner reading ""Macron, withdraw your plan; save and improve our retirements," heading for Gare de l'Est, four kilometres (2.5 miles) to the north, an AFP reporter said.
Reaching the opera house at Bastille square, some demonstrators shouted "we don't want the grandfather clause" referring to proposals for new opera dancers to lose the current generous pension benefits enjoyed by older colleagues who can currently retire at 42.
So far, more than 60 performances at the Paris opera's historic Garnier and modern Bastille stages have been cancelled, leading to losses of more than €12 million in ticket sales.
Several other professions, including train drivers, also enjoy special pension provisions. Macron wants to simplify the system and is banking on support falling for the strikers the longer the disruption goes on amid what is now the longest continuous train strike in French history.
Some 3,500 protested in Paris, according to police figures. Smaller marches took place in the southwestern cities of Marseille and Toulouse.
A new poll published Friday showed a majority of 61 percent still support the strike, although that was five points lower than a December 19 survey, according to pollster Odoxa.
The strikes have been ongoing since December 5, upsetting travel plans and hitting shops and other businesses over the key Christmas period.
After a month of disruptions, Macron will on Monday hold his first cabinet meeting of 2020. The following day discussions with union leaders are set to resume, but so far neither side has appeared ready to give much ground.
Unions have called another day of mass demonstrations for Thursday, when teachers, hospital workers and others are expected to join the strike.