Nearly a million French people took to the street on Saturday to start a new round of protest against President Nicolas Sarkozy's plan to raise the retirement age.

The Interior Ministry estimated some 825,000 people marched in cities across France, calling for the right to retire at 60.

The largest crowds gathered in Paris, mainly blaring music and chanting. Around 30 people were arrested in central Paris for setting rubbish bins on fire and throwing smoke grenades. In Marseille, people blocked schools and public transport.

France's upper house of parliament has already voted to prolong the retirement age from 60 to 62 years old. On Monday, it approved increasing the full-pension age regardless of contribution period to 67 from the present 65.

Fuel supplies of all France's 12 refineries were hit since refinery workers joined the nationwide demonstration called by trade unions last Tuesday and fearful motorists rushed to pump oil.

The government asked some flights landing in France to bring with enough fuel to return home as possible fuel shortages may occur in France's main airports after this new round of protest.

Unions warned that the strike will affect more businesses and the sixth round of nationwide protest will start Tuesday, a day before the Senate votes on the retirement bill.