Some 3.5 million people marched in the streets of France Tuesday to protest against President Nicolas Sarkozy's pension reform, unions said, dpa reported.
The sixth day of nationwide protests against the measure since early September was accompanied by job stoppages and a growing number of service stations running out of petrol as a strike at France's 12 oil refineries went into a seventh day.
While the Interior Ministry put the number of demonstrators at only 1.1 million, Environment Minister Jean-Louis Borloo said that some 4,000 service stations, out of a total of 12,500, were in need of re-supply.
The government began to act to ease the petrol shortfalls, with an emergency meeting held in Sarkozy's offices at the Elysee Palace to draw up appropriate measures.
The protests were marred by renewed violence Tuesday as secondary-school students again took part in the movement.
A middle school in the city of Le Mans burned down overnight following a student protest during which the gates to the school were blocked. Police suspect arson, France Info radio reported.
There were clashes between police and protesting youths in several cities, such as Nanterre and Lyon, with protesters hurtling projectiles and setting cars on fire, and security forces replying with teargas.
Several police officers and a news photographer were injured in the skirmishes. In addition, a 15-year-old girl was taken to hospital in Paris after being injured when a motor scooter was set on fire and exploded.
In the centre of Lyon, stores were ransacked by hooded youths. The interior ministry said more than 1,150 protesters were arrested in the last week following violent incidents.
A police spokesman told BFM television that the violence was primarily the work of "anarchists" and young people from poor suburban ghettos who were using the demonstrations as a pretext to attack police.
In the coastal resort of Deauville, where he met with German Chancellor Angela Merkel and Russian President Dmitry Medvedev, Sarkozy said he would take measures "to guarantee order."
A strike of railway workers also went into its seventh day Tuesday. The state-run railway network SNCF said about one-half of all scheduled trains were not operating.
The French civil aviation authority DGAC said that 50 per cent of all flights originating at Paris's Orly Airport had been scrubbed Tuesday, with 30 per cent cancellations at other French airports.
The DGAC said that there would be more flight cancellations on Wednesday, with about one in four scheduled flights annulled at Orly.
The pension reform will gradually raise the retirement age from 60 to 62 by the year 2018. It has been approved in the National Assembly and is set to be voted on in the Senate later this week.
With the measure almost certain to become law, it was unclear Tuesday what the unions' next step would be.
In 1995, a 24-day general strike that paralyzed the nation moved then prime minister Alain Juppe to drop his plans to reform the pension system.