The return of bad weather has brought school closures and traffic disruption to the isles for the second time this month.
All schools were closed on Friday following a bout of heavy snow overnight. Roads have remained treacherous with visibility severely reduced across the isles.
Snow-ploughs have been out in force to clear as many routes as they can, although they will be concentrating on the main roads before turning their attention to the side roads later on.
With several vehicles having crashed and others stranded, police are advising motorists against all travel.
A spokesman said: “Road conditions in Shetland have deteriorated significantly within the last two hours owing to the heavy snowfall.
“Police are now advising against all travel. We are currently trying to respond to a number of reports of motorists stranded on the roads in Shetland and have taken reports of a few vehicles which have crashed as a result of the adverse weather.”
Services at Sumburgh Airport have also been disrupted by the snow – flights to or from Aberdeen, Edinburgh and Kirkwall were all affected during the morning.
Airport manager Nigel Flaws said conditions had effectively forced the airport to close. The paper and mail planes failed to arrive.
The disruption is partly caused by bad weather down south. Operations at Inverness Airport came to a halt this morning while Kirkwall and Glasgow Airports also had problems.
Mr Flaws said airport staff would do their best to allow flights through later on should their be a break in the weather, but warned conditions had been fairly bad so far.
“It’s been blowing fairly strong and snowing fairly hard. If it stops snowing we’ll be out blowing it away as quickly as we can to help services return to normal,” he said.
Inter-island flights to Foula and Fair Isle from Tingwall Airport have also been cancelled.
Snow also brought disruption to oil-related flights at Scatsta Airport. No flights were getting either in or out of the airport.
There is no end in sight for the bad weather, either. Snow showers with northerly winds will continue on Friday night, while cold, windy and wintry showers are expected to affect the isles on Saturday. Forecasters expect the cold to continue into next week as well.