Thousands of people demonstrated on Saturday against French President Emmanuel Macron's proposed pension reforms which have sparked a month-long transport strike.
Police briefly used the tear gas in the city's Bastille area and at the Gare de l'Est railway station.
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 project; save and improve our retirements,' heading for Gare de l'Est, 2.5 miles to the north, according to someone at the scene.
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 £10.2 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.
A new poll published Friday showed a majority of 61 per cent still support the strike, although that was five points lower than a December 19 survey, according to pollster Odoxa.
Unions have called another day of mass demonstrations for Thursday, when teachers, hospital workers and others are expected to join the strike.
President Emmanuel Macron has said reforms are essential to simplify the current convoluted pensions system, but his opponents say they will result in many French people having to work for longer.
'People have to think a bit about what kind of society they want in general and, on a more personal level, whether you're 20, 30, 40 or 50, one day you'll retire,' said Jean-Gabriel Maheo, an industrial technician who said he was in his fifties.
'If the currently proposed system passes in the way it is laid out, it will be a social catastrophe.
Already, the previous reforms are seeing people retire with measly pensions,' added Maheo, as he took part in the Paris demonstration on Saturday.
Much of France has been crippled by a national transport strike since the anti-pensions protest first began in early December.
This article has been adapted from its original source.
