Temperatures fell to around minus 10C in Norfolk last night with a severe frost and freezing fog becoming more widespread.

Police and authorities have warned drivers to be cautious on the roads, particularly during the rush hour although neither the police nor the fire service reported any major incidents.

At 6.30am there were 32 schools shut.

Postal deliveries and collections have also been disrupted largely in Norfolk's rural areas, due to the combination of heavy snowfall and freezing temperatures.

Royal Mail confirmed areas around North Walsham, Cromer, Sheringham, Fakenham, Holt, Attleborough, Wymondham and Dereham were affected.

Royal Mail spokeswoman Morag Turnbull said: 'We apologise to those customers who have experienced delays to their deliveries as a result of the severe weather conditions in Norfolk.

'We are continuing to deliver where it is safe to do so but, in some cases, it is not possible to because of the weather.

'A range of measures have been put in place to ensure deliveries reach people as quickly as possible.'

Gritters had completed an afternoon run on the roads, which Norfolk County Council said should be enough to keep them safe through the evening.

However, the council and police have issued renewed appeals to drivers to drive carefully, as temperatures plummet, leading to black ice and freezing fog, and reminded them to allow extra time for journeys given the conditions.

People walking home, and those who have chosen to leave their cars in favour of travelling home on foot, should also beware slippery pavements caused by the compacted snow, or melted snow turning to ice as dark falls.

A spokesman for Norfolk County Council said gritters had been out on an afternoon road treatment run at 1pm, but another run was not expected until 12.30am.

He said: 'We will make a decision on an evening run depending on any change in the conditions. We will definitely be going out after midnight, and there will be a run at 4am.

'We will assess the state of the roads, but adding more salt this evening may not do any good.

'Though the treatments are down, it's still important people understand that they must still drive with great care.'

Medical secretary Sophie Hughes, who abandoned her car at the Norfolk and Norwich University Hospital yesterday and had to walk the 5.5 miles home to Wymondham, decided to brave the roads this afternoon and was relieved to get home in 30 minutes.

'The access roads to the NNUH, Thickthorn roundabout and the B1172 are all clear and traffic is flowing, albeit very slowly,' she said.

Temperatures have remained below freezing in most part of Norfolk today, though fresh snowfall has been kept to a minimum.

A number of schools in the Dereham area have already announced they will be shut on Thursday as the icy blast continues to bite.

Dereham Neatherd High will be closed but the town's other high school, Northgate, will be open.

Dereham Sixth Form College will also be closed, although exams will go ahead.

Litcham High and Junior, Brisley Primary, Great Dunham Primary, Toftwood Infants, Dereham Church Infants and Scarning will all be shut.

Other schools in the Dereham, Fakenham and Wells areas have yet to say what they will be doing.

Temperatures have remained below freezing in most part of Norfolk today, though fresh snowfall has been kept to a minimum.

The weather has been bright and sunny all day in Mid Norfolk – but temperatures have remained below zero.

Roads which have been gritted have been generally clear but untreated roads have been treacherous. Paths in the town centres are very slippery and lots of people have fallen over. There have been no reports of serious injuries. Many people have complained about the lack of clearance of pavements in the towns.

Snow began falling and settling between Norwich and Fakenham at around 5pm, and freezing fog between Dereham and Swaffham is getting worse.

As temperatures plunge later, conditions on all roads are expected to become very dangerous again.

Breckland Council said all recycling rounds and garden waste rounds are currently suspended, but residents are asked to keep bins out.

King's Lynn and West Norfolk is in a shroud of freezing fog with icy conditions.

Temperatures have not risen above freezing all day, while Marham was one of the coldest places in Britain last night.

There has been the occasional flurry during the afternoon, but no great amount of snow accumulating in the town or surrounding area.

Roads are clear, though there is freezing fog thickening in the Fens, with visibility down to just 50m on the A47 between King's Lynn and Wisbech. Police have reminded motorists to use their headlights.

At 4pm, Cromer town centre itself did not have much snow or ice but Holt, Aylsham, North Walsham, Stalham and Sheringham and surrounding north Norfolk villages were still suffering with deep snow and ice.

The main roads are passable but smaller country roads are more dangerous. One Banningham resident said the roads in the village, near Aylsham, were like an ice rink.

The snow has still not reached Great Yarmouth or Lowestoft.