Britain remained under an icy grip this morning after overnight temperatures plunged as low as minus 12, closing schools and causing chaos on the roads.

It was too cold for classes to take place at the 50-pupil Ysgol Rhewl in Ruthin, after thieves stole the heating oil for the primary school in North Wales.

Thirty schools in Cumbria were closed after the region was covered in up to 8cm of snow and icy road warnings were in force throughout north-west England, Yorkshire and Humber and the East and West Midlands.

It was the South of England that bore the brunt of the cold last night, however, with the lowest temperatures recorded in Benson, Oxfordshire and Chesham, Buckinghamshire below that recorded in parts of Iceland and Greenland.

Experts say the prolonged cold snap is set to last out the week.

Freezing fog swathed parts of the country causing hazardous road conditions. Thousands of motorists were left stranded yesterday in the Arctic temperatures and the AA and RAC have come to the rescue of 50,000 drivers in the past two days with the greatest surge of breakdowns in Bristol, Bournemouth, London and Birmingham.

Tonight’s frosts won’t be as severe as recent days, according to the Met Office, as temperatures will dip to a relatively mild minus one to two degrees but they are not set to rise much above 5 degrees until the weekend.

Daytime temperatures today were expected to creep up a couple of degrees to a maximum of 5C (41F), with the northern half of Britain faring better than the rest.

Meanwhile, the water supply to 6,000 homes in the Rhondda valley, south Wales, continues to be affected by frozen pipes. In central London, shivering tourists witnessed the unusual sight of frozen fountains in Trafalgar Square.

Heating bill pay-outs to pensioners and the vulnerable have now topped £100 million as the Government stepped in to help. The £ 25-a-week pay-out is triggered when an area’s average temperature falls to 0C (32F) or below for seven consecutive days.

The elderly were advised to take extra precautions to make sure they stayed warm as a charity claimed that more than 12 pensioners could die every hour.

Among the victims of treacherous road conditions was a woman cyclist who suffered serious injuries when she was run over by a Land Rover which skidded on ice in Clevedon, Somerset.

In Dorset, a man escaped injury when his BMW 325 convertible spun off the road and hit a telegraph pole near Bournemouth International Airport just after 6am. Meanwhile in Devon and Cornwall, police warned drivers to delay journeys after seven crashes including two multi-car collisions.