More than a million people have joined a day of protests and strikes, according to France's interior ministry, against plans to push back the age of retirement from 62 to 64.
President Emmanuel Macron called the reforms "just and responsible" - but they are facing a make-or-break moment. The strikes severely disrupted public transport and many schools were closed.
Out of the country for a French-Spanish summit in Barcelona, President Macron said, the measure, a central pillar of his second term, is needed to keep the pension system financially viable. However, unions say it threatens hard-fought worker rights. In a country with an aging population and growing life expectancy where everyone receives a state pension, Macron’s government said, the reform is the only way to keep the system solvent.
Police were out in force in Paris in case of violence from ultra-left "black bloc" infiltrators but there were few clashes and 38 arrests. Prime Minister Élisabeth Borne praised both the police and the unions for the "good conditions" in which the protests had taken place.
Paris police said, 38 people were detained as a mass of people thronged the streets of the capital despite freezing rain. Retirees and college students were among the diverse crowd.