Earlier in the day, it was reported about 65 detainees in the French capital.
The mass rally began at around 2.00 p.m. (13:00 GMT) at the Paris Est Train Station, en route to Place de la Nations. Among the strike's organizers were a number of the largest trade unions in France. To ensure security in the French capital, 6,000 police officers and gendarmes were mobilized.
The French Interior Ministry estimated that over 800,000 protesters took to the streets across France to rally against the controversial pension reform. The French government has recently proposed replacing a generous pension system with a points-based scheme, angering railroad employees, teachers, police and other public workers.