Trains, schools, public services and ports have since January been disrupted by strikes against the proposed reform.
A rolling strike by municipal garbage collectors in Paris has left about 10,000 tonnes of trash piled up in the streets, according to the mayor's office, attracting rats and putting off tourists.
Unions from national train operator SNCF Friday meanwhile urged workers to continue a rolling strike that has caused major disruption on the network.
Already on Thursday night, police used tear gas to clear demonstrators after a fire was lit at the Place de la Concorde, and similar scenes unfolded across France.
The ensuing unrest saw 310 people arrested around the country, including 258 in Paris, Interior Minister Gerald Darmanin said.
"The opposition is legitimate, the protests are legitimate, but wreaking havoc is not," he said.
According to polls, two-thirds of French people oppose the pensions overhaul.