Police officers are trying to disperse the protesters with tear gas.
Protests are also taking place in other cities in France, including Rennes.
In Nice, 5.2 thousand people took part in the protest against the pension reform.
In Toulon, according to police, 12,<> people came out to protest.
On March 20, the National Assembly of France rejected a vote of no confidence in the government of the republic due to the pension reform, put forward by the faction of Marine Le Pen's party "National Rally".
Before that, another vote put forward by the opposition group LIOT was rejected.
On March 16, French Prime Minister Elisabeth Bourne announced the adoption of a law that increases the retirement age from 62 to 64 years.
The law was passed bypassing a vote in the lower house of parliament.