Paris: French truckers blockaded fuel and food supply depots on Tuesday as marchers took to the streets in a further wave of nationwide protest against labour law reforms but President Francois Hollande said he would not back down.
Police arrested eight people after violent incidents on the fringes of a march in the western city of Nantes, while a Paris street rally was marked by skirmishes between masked youths and police who used tear gas to disperse them.
With a train strike set to start later in the day, the week has been billed by French media as a make-or-break moment for a protest movement that has appeared to lose steam after months of sometimes violent demonstrations.
Hollande, whose popularity is at rock bottom a year before a presidential election, said he would not scrap the changes to one of Europe's most protective labour laws - a flagship reform that would make hiring and firing easier.
"I will not give in," the Socialist leader told Europe 1 radio.
Police evacuated a FNAC consumer goods store in Nantes targeted by troublemakers. CGT union members in the southern city of Toulouse used concrete blocks to seal off the window of a Socialist Party office, while scuffles broke out at the start of a march in the capital.
The truckers slowed or blocked traffic on major roads and at strategic points, notably in the Bordeaux region of southwestern France, where they turned away deliveries to a supermarket and fuel supply hubs.
Scores of protesters gathered in Paris for a large afternoon march led by CGT leader Philippe Martinez. They were joined by backers of the Nuit Debout protest movement (which loosely translates as "Night Uprising") that sprang up in response to the labour reforms.
The SNCF railway predicted sharp reductions in regional, intercity and high-speed services when state train workers stop work for a protest running from late Tuesday to Friday morning.
Hollande said 1,000 people had been arrested and more than 300 police injured during the clashes of recent months, with some troublemakers travelling from overseas to join the unrest.
"People have a right to protest, but rioting is an offence that will be punished," he said.
Last week, police figures suggested a significant dip in turnout at rallies, with a tally of 55,000 for a May 12 protest versus 390,000 at a similar event at the end of March.
The hardline CGT and smaller unions have called for rolling strikes by rail workers, dockers and airport staff over several weeks, as well as demonstrations on Tuesday and Thursday.
At Total's 219,000 barrels-per-day Donges refinery in western France, CGT official Christophe Hiou said "not a drop" of oil or fuel was entering or leaving the facility. Workers are considering further action in coming days, he said.
Salaried truckers say they will be among the first to suffer under the new law, which would allow road haulage firms to back out of overtime pay deals that often account for thousands of euros of a driver's annual pay packet.