Journalists and rights organisations have criticised the new law, arguing that it shields French police from scrutiny.
The police said there was unacceptable violence occurring near the Gare de Lyon on the margins of a concert.
French labour unions were divided about the future of the social movement after the government offered to temporarily scrap a controversial part of its pension reform. plans.
Americans are increasingly striking and protesting for economic improvements, with support for unions reaching its highest level in decades.
French farmers are protesting against low incomes and government policies they say negatively affect France's agriculture.
"Exhausted caregivers = endangered patients", "Public hospitals in life-threatening emergency" were some of the protesters' mottos.