According to an earlier statement by the General Labor Confederation (CGT), the mobilization witnessed the participation of over 900,000 people across the country, with 300,000 of them gathering in Paris.
Paris police said that only 31,000 people were present in the city.
Trade unions and workers are persistently expressing their opposition to the government's pension reform, which was adopted on March 16 and is scheduled to come into effect on September 1.
The Paris police headquarters announced that 17 people were arrested during the demonstration in Paris.
Meanwhile, BFM TV channel reported that five people were arrested in Rennes and a police officer was injured in the knee.
French authorities expected around 400,000 to 600,000 people to join the nationwide protests, with 40,000 to 70,000 anticipated in Paris.