France was plunged into a new level of chaos by protest strikes today with hundreds of flights cancelled, huge queues at filling stations and train services cut by half.
The demonstrations against plans to raise the national retirement age from 60 to 62 also turned violent with masked youths fighting with police and starting fires in cities across France.
President Nicolas Sarkozy pledged to crack down on "troublemakers" and guarantee public order, raising the possibility of more confrontations with rioters after a week of disruptive but largely non-violent demonstrations.
Mr Sarkozy also promised to ensure that fuel was available to everyone. Around 4,000 filling stations were dry by this afternoon, with long queues at others.
Prime minister Francois Fillon said oil companies agreed to pool stocks to try to get supplies flowing.
"The government will continue to dislodge protesters blocking the fuel depots. ... No one has the right to take hostage an entire country, its economy and its jobs," he said.
The protesters are trying to prevent the French parliament from approving the new retirement age aimed at helping prevent the pension system from going bankrupt.
The measure is expected to be passed this week, although plans to move it through tomorrow have been delayed in the wake of political attempts to derail it.
Many workers feel the change would be a dangerous step in eroding France's social benefits - which include long holidays, contracts that make it hard for employers to lay off workers and a state-subsidised health care system - in favour of "American-style capitalism."
In Paris today huge crowds marched toward the gilded-domed Invalides, where Napoleon is buried. Police estimated the crowd at 60,000, down from 65,000 at a similar march last week.
At a school in the Paris suburb of Nanterre youths started throwing stones from a bridge at police, who responded with tear gas.
At the Place de la Republique in eastern Paris youths pelted riot police while in Lyon they set fire to rubbish bins and were met with clouds of police tear gas.
Up to half of flights out of Paris' Orly airport were scrapped today, and a third of those from other French airports, including the country's largest, Charles de Gaulle, serving Paris, were cancelled.
Most were short- and medium-haul domestic and inter-European flights. The walkout by air traffic controllers was expected to last one day, with flights expected to return to normal tomorrow.
Bordeaux, scores of protesters blocked the airport entrance for several hours.
The fuel shortages are being caused by striking oil refinery workers. "There are people who want to work, the immense majority, and they cannot be deprived of fuel," Mr Sarkozy said.
Police in Grand-Quevilly moved protesters blocking a fuel depot, which had been completely sealed off for a day.
Meanwhile almost 400 schools across the country were blockaded or disrupted, the highest figure so far in the student movement against the retirement reform.
The head of the UNEF student union, Jean-Baptiste Prevost, said the students "have no other solution but to continue."
"Every time the government is firm, there are more people in the street," he said.
With disruptions on the national railway entering their eighth consecutive day many commuters' patience was beginning to wear thin. Only about one in two trains were running on some of the Paris Metro lines, and commuters had to fight onto packed trains.
The SNCF railway operator said only about half the regularly scheduled high-speed TGV trains linking Paris to regional French cities were operating, while fast trains between regions were slashed by 75%. The Eurostar, which links Paris to London, was unaffected.
In Marseille, strikes by binmen left heaps of rubbish piled along pavements.