The worst snowfall to hit the country in 18 years has caused problems for Bristol's trains and planes.

First Great Western trains has advised against travel unless necessary, as services between Bristol Temple Meads and London Paddington were partly disrupted.

Bristol International Airport has remained open on Monday but the weather caused "some delays and a small number of cancellations", a spokesman said.

When snow covered the runway at 1.30pm, four incoming flights, from Milan, Krakow, Alicante and Dublin, were diverted to Bournemouth, Exeter and in the case of both Krakow and Dublin, to Cardiff.

A spokesman for the airport said Ryanair and easyJet were experiencing delays across their network which were affecting Bristol departures.

In Bristol, snow fell throughout the afternoon but just one school closed in the city, due to a heating fault that was not weather-related. So far no roads have been reported blocked.

Other areas across the region have been harder hit and drivers have been urged to take care on the roads as more bad weather is forecast.

Teams from Gloucestershire County Council have been out through Sunday and from early Monday morning gritting the roads.

The council said the A4173 at Brookthorpe, the A4136 at Nailbridge and on the B4008 at Quedgeley are particularly icy and gritters have been dispatched to deal with these problem areas.

The Met Office is predicting heavier snow to fall overnight with up to 5-10cm likely in many areas with as much as 20-30cm possible, especially over higher ground.

Across Gloucestershire 21 schools are currently closed and around six schools were closed in Bournemouth, 17 schools and three pre-schools in Poole and 48 in the rest of Dorset.

Gloucester Councillor Stan Waddington, cabinet member for environment, said: "Our 32 teams of gritters have been working hard all night and this morning to keep the roads clear and help people get to work safely.

"These teams will remain out on the roads for the rest of the day and tonight to try to keep the county moving safely. But with more bad weather expected later today (Monday), I would urge all drivers to take extra care on the roads and only use your car if it is really necessary."

Helen Chivers, a forecaster with the Met Office, said the last time the UK saw such widespread snowfall was in February 1991. "And we're going to get more," she said.

A spokesman for the Highways Agency said: "If your journey is not essential I would strongly advise you don't make it."