Hundreds of schools have been closed, dozens of flights and train services have been cancelled and a number of serious crashes reported as heavy snowfall hits the UK.

The treacherous conditions are expected to cause misery for commuters heading home on Tuesday evening, amid warnings there will be no let up in the icy blast.

Temperatures across most of the UK fell below freezing in the early hours of Tuesday, with the mercury dropping to -8.9C in Farnborough, Hampshire, overnight.

On the roads, there have been a number of serious collisions as drivers were warned to take extra care when making their journeys.

:: Live updates – Travel chaos as snow hits UK

Three people died following a crash involving a car and a lorry on the A15 at Baston in Lincolnshire. Police say the road conditions at the time will form part of their investigation, adding it was snowy at the time.

A man was killed after a three-car collision on the A47 in Cambridgeshire, while another man suffered possibly life-threatening injuries after a van hit a tractor carrying a livestock trailer on the A30 in Devon.

Long delays were reported on the M20 in Kent and the M62 in Merseyside after serious collisions.

Many roads were closed, with police reporting treacherous driving conditions and blocked routes.

There were 20 crashes within three hours on Lincolnshire’s roads, including a school bus with 45 children on board.

The pupils were unharmed after their bus hit a car and veered off the road, Lincolnshire Police said.

Meanwhile, hundreds of schools have been closed in Wales, East Sussex, Essex, Kent, North Yorkshire, Norfolk, Lancashire, West Yorkshire, Surrey and Staffordshire.

Hundreds of trains and dozens of flights have also been cancelled as a result of the conditions.

Commuters experienced cancellations and disruption on lines across the country, with the majority of operators warning passengers to expect problems.

Southeastern cancelled dozens of trains, while other operators affected include Southern, Greater Anglia and Great Northern.

Passengers were also warned to expect delays and cancellations on c2c, London Overground, South Western Railway, Stansted Express and TfL Rail.

British Airways said it had cancelled 68 short-haul flights, while easyJet also warned of disruption.

Conditions are not likely to get better for a number of days, with forecasters predicting the snow will continue well into the week.

Amber warnings for snow were in place for the South East, North East and East Midlands until midday on Tuesday, with a yellow warning in force for much of the country until midnight.

Forecasters have predicted 5-10cm of snow for most areas of the UK, with 40cm possible on higher ground in Scotland.

The wind chill, which could see parts of the country drop as low as -15C (23F), is on par with forecasts for parts of northern Norway and Iceland.
(c) Sky News 2018: UK snow: Temperatures plunge to -9C as big freeze takes grip