Paris: Thousands of travellers were stranded at Paris' main airport on Friday as freezing conditions forced the cancellation of nearly 60 flights, with the prospect of further delays into Christmas Day.

French aviation authorities said they had cancelled half of the flights serving Paris Roissy Charles-de-Gaulle airport until 1:00 pm (1200 GMT) on Friday because they were struggling to de-ice aircraft in the extreme conditions.

And Transport Minister Nathalie Kosciusko-Morizet, who visited the airport late on Thursday, warned that the delays could, for some passengers, extend into Christmas Day.

"There have been 58 flights cancelled this afternoon at Roissy, essentially because of a problem de-icing" the aircraft, Kosciusko-Morizet said.

"Fifty-eight flights, that represents 6,000 to 7,000 passengers," of whom 2,000 were in the airport itself in the small hours of Friday morning, she added.

And according to their calculations, about half of the delayed passengers might not be able to get a flight out on Friday, Christmas Eve, she warned.

Forecasters were expecting below-freezing conditions on Friday morning and the airport was having trouble getting hold of enough glycol, the liquid used to de-ice aircraft, aviation officials said in a statement late on Thursday.

Civil aviation officials had therefore asked all airlines to reduce their flights by 50 percent, the statement added.

Aeroports de Paris (ADP), the company running the capital's airports, had said earlier on Thursday that the de-icing process had been taking 25 minutes instead of the usual 14, because of the extreme conditions.

Charles de Gaulle airport had only just cleared the backlog from the delays caused earlier in the week by the freezing conditions, which on Monday saw thousands of passengers forced to spend two nights running sleeping there.

Kosciusko-Morizet and junior transport minister Thierry Mariani visited the airport late on Thursday to see the situation for themselves, their offices told AFP.

Of the passengers unable to travel, some local people returned home, others were put up on nearby hotels and two gym halls opened by local authorities, said an airport official.

Air France said it had provided 3,500 hotel rooms for its customers.

At the airport itself meanwhile, officials set up hundreds of camp beds for passengers with nowhere else to go.

"It's unacceptable!" protested one man, who had been due to fly to Casablanca, Morocco for his brother's wedding.

"Everyone's blaming each other, the company, the airport management," said his tearful wife.

"They've been giving us the runaround all day in the airport without taking into account the fact that I'm pregnant," she added.

In Britain, the operator of London's Heathrow airport said on Thursday it had launched an external inquiry into the handling of the snow chaos that left thousands of passengers stranded there earlier in the week.

Spanish-owned operator BAA announced the inquiry as Heathrow, the world's busiest airport for international passenger traffic, began to get back on track with around 90 per cent of flights operating after days of cancellations.

Politicians in Britain, France and the European Union have already expressed dissatisfaction at the inability of some of Europe's major airports to cope with the heavy snow.