Teachers, doctors, railway workers, and other public sector employees marched peacefully through cities across France on Tuesday (December 10).
But commuters still had to grapple with chaos on the sixth day of revolt against President Emmanuel Macron's pension reform.
Demonstrators were heeding a call by trade unions to stage one of the biggest protests in decades, though union officials said one last week saw a bigger turnout.
Dozens of schools closed, airlines canceled 20 percent of flights and refineries halted distribution.
As well as Paris, Lyon, Marseille and other major cities saw huge protests.
In Lille, high school students ran from police who fired tear gas.
Unions urged workers to turn the screws on Macron the day before his government unveils its pension proposals.
Former investment banker Macron is determined to simplify a system of more than 40 pension plans that provide some of the world's most generous benefits.
The unions are showing no sign of backing down in a battle that could define his presidency.
These strikes are among the biggest since 1995, when Prime Minister Alain Juppe was forced to abandon his plans to overhaul the pension system after weeks of industrial action.