The rallies came as a 24-hour national strike disrupted flight and rail services, and closed schools.

Activists are angry at government plans to overhaul pensions and raise the retirement age from 60 to 62.

Union leaders say more strikes and protests are possible if the government fails to give an adequate response.

“If they don’t respond and they don’t pay heed, there’ll be a follow up, and nothing is ruled out at this stage,” Bernard Thibault, leader of the large CGT union, told a rally in Paris.