A young woman crosses Westminster Bridge in London as a deep freeze sweeps across the country this week. (Jas Lehal/Reuters)

Britons faced icy roads and cold temperatures Thursday after a heavy snowfall that disrupted travel and forced the closure of thousands of schools..

The temperature fell to –18 C overnight in some places, and forecasters say the cold snap brought by an arctic weather system will continue through next week. Some areas of the country received up to 50 centimetres of snow.

Britain is experiencing its longest cold snap since 1981, the national weather service said.

Up to 25,000 homes have been affected by power cuts in southern England since Wednesday morning, the BBC reported, and about 4,000 remained without electricity on Thursday.

Motorists were warned of icy roads. While most major routes were open, drivers were thwarted by accidents, delays and abandoned vehicles, the BBC said.

At least two people were killed in crashes, and a man's body was found under the ice of a frozen pond at a country club in Frimley Green, southwest of London. Police are investigating.

Earlier this week, Britain's military and coast guard services were brought in to help rescue hundreds of stranded motorists. Up to 1,000 vehicles were caught in a massive snow-related traffic jam in Hampshire, in southern England.

Major airports, including Heathrow and Gatwick, were open, but hundreds of flights were cancelled because of snow and ice, and passengers were warned to expect delays.

Delays were also expected for rail service in some parts of the country, and thousands of schools were to remain closed.

The Automobile Association said it had dealt with thousands of incidents across the country since the onslaught of the storm and sections of major highways had been closed.

With files from The Associated Press