French postal workers, airport staff and drivers joined with refinery workers and masses of citizens Tuesday in a sixth day of nationwide strikes and protests against President Nicolas Sarkozy's plan to raise the retirement age.

Students clash with the police during a demonstration over pension reforms with private and public sector workers in Lyon October 18, 2010. [Xinhua]

Tuesday's demonstration came after long strikes at refineries and blockades of some fuel depots, which hit the country's fuel supply and forced the government to tap strategic oil reserves to avoid shortages.

About 2,500 petrol pumps out of a total of 12,500 stations are out of fuel, leaving queues of panicking motorists, though officials repeatedly dismissed risks of fuel shortage.

France's Civil Aviation Authority estimated a 50-percent decrease in flights at Orly airport while Paris Charles de Gaulle airport expected to delay 30 percent of its flights.

Train traffic was disrupted with only one in three high-speed TGV trains on the rail network running.

High school students were set to join the massive protests with 379 secondary schools affected by protests.

Protests also turned violent Monday during youth demonstrations held in Paris and in the south after students torched several cars and caused damage to other vehicles. There were 22 policemen injured and 196 students arrested across the country by Monday, according to local reports.

In Mans, a city not far from Paris, a school was completely destroyed after being set afire. Officials said no link had been established so far with the student movement but the cause was "likely criminal."