Heavy snow and frigid temperatures caused further disruption across northern Europe on Monday - stranding travellers, snarling traffic and shutting schools.

More than 1,000 flights at Germany's main airports in Frankfurt, Munich and Berlin were cancelled and many more delayed after up to 40 cm (16 inches) of fresh snow blanketed the country. Some 500 stranded passengers slept on cots at Frankfurt airport.

Airlines advised passengers to switch to trains if possible after the new snow added to two week's worth of accumulation but rail operator Deutsche Bahn, struggling to cope with packed trains and a crush of passengers, urged passengers to stay home.

Tempers flared as Germans accustomed to timely trains and planes were forced to wait in freezing stations or packed terminals, and the unusually heavy snow delayed millions of commuters.

Meteorologists warned there was more snow to come.

'The trains are always too late now,' said Lothar Ast, 57, a custodian shivering in a Berlin station. 'They're so crowded that you can't get on and then you have to wait for another.'

Dorothea Fuerst, a Berlin sales clerk, added: 'No one knows if the train will come or not. The train never arrives on time. Will it be 15 minutes or half an hour? That's the question.'

Children's sledges were sold out in Germany, retailers said.

'This much snow is only fun if you're a kid,' said Berlin lawyer Katja-Julia Fischer, 42: 'It's getting on my nerves.'

Germany's most populous state, North-Rhine Westphalia, took the unusual step of banning trucks from motorways in a bid to keep passenger traffic rolling. A rail worker was killed in Berlin, run over by a train while trying to de-ice a switch.

Belgium also closed its motorways to truck traffic after there was a peak of 600 km of traffic jams at the height of the rush hour on Monday morning in the Wallonia region.

In the United Kingdom, British Airways said the severe weather continued to cause significant disruption to operations and further travel chaos was possible on forecasts of more snow.

Only one of two runways at London Heathrow, the world's busiest international airport, was operating after the snowstorm paralysed the airport over the weekend, stranding thousands.

Other UK airports were open, but many flights were cancelled or subject to long delays, and many passengers spent a second night at an airport terminal.

'There is the risk of further snow across parts of southern Britain tonight and through tomorrow,' said Met Office chief forecaster Steve Willington.

The severe weather has hit retailers at the height of  Christmas trading. Britain's biggest department store chain, John Lewis, said sales fell more than 10 per cent on Saturday, while France's Auchan said its business was being affected.

Some online retailers are not accepting new orders or are cancelling existing ones because of delivery problems, according to industry body IMRG.

Northern France was also covered by heavy snow, disrupting road and rail traffic as Parisians braved clogged highways to reach their holiday destinations.

Air travel was reduced at Paris's two main airports, with Orly airport shutting down briefly and stranded travellers still camping out in the waiting areas at Charles de Gaulle.

Train travel between Paris, London and Brussels on the Eurostar line was disrupted, partly becaue of speed restrictions, the company said on its website, adding that sales were closed for travel up to and including December 24.

In Poland, hard hit by the cold snap, six people froze to death on Sunday night, raising the death toll to 114 in the last month. Heavy snow snarled Warsaw traffic again on Monday. Warsaw airport was open but was receiving far fewer passengers than usual because of flight cancellations in western Europe.-Reuters