Paris and northern France braced for weather chaos Wednesday, with the authorities cancelling flights and telling people to leave work early and stay off the roads ahead of anticipated snowfall.

Around 15 percent of flights at Paris Charles de Gaulle are to be cancelled on Wednesday evening and 20 percent at Charles de Gaulle and Orly airports on Thursday, civil aviation authority DGAC said in a statement.

Paris police authorities told businesses in the Paris region to let their employees go home from 4 pm (1500 GMT) and advised drivers to stay off the roads "unless absolutely necessary."

"During the coming hours, some sections of road or motorway might be temporarily closed to all traffic," police said in a statement.

An inter-ministerial crisis centre said that between five and 10 centimetres (two and four inches) of snow would fall from the early evening, and authorities have issued a weather alert for 20 regions in northern France.

The government was heavily criticised for its perceived slow reaction to two heavy snowfalls this month, with a dump on December 8 and 9 forcing thousands to spend the night in their cars or improvised camps at public buildings.

Heavy snowfall hit Charles de Gaulle and Orly airports on Sunday and Monday, with thousands of passengers forced to spend a night or two in the terminals.

Eurostar rail services connecting Paris and Brussels with London were however slowly returning to normal on Wednesday, with 90 percent of trains running after three days of chaos, a spokeswoman said.

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