More snow and ice is forecast for Scotland after a day of travel disruption as winter weather swept in.

Heavy snow lying in the north, south and west of the country led to problems on many roads and police said they dealt with "dozens" of minor accidents as cars skidded off roads.

A four-car crash on the M74 brought a rush hour standstill on Thursday morning, while freezing conditions on the M77 in Ayrshire led to long tail-backs in the afternoon and the A9 was hit by two lorries coming off the road.

Even Olympic champions were caught up in the bad weather, with former cyclist Sir Chris Hoy taking to Twitter to thank a gritter driver who helped tow his car out of a snow bank in the south of Scotland.

He wrote: "Thanks 2 the kind gent who towed my car out of a snow bank today after I hit black ice. Thankfully no harm to me or car but be careful folks!"

Dumfries and Galloway Council posted a picture of Sir Chirs with the driver on Twitter and wrote: "Gritter driver Stevie went beyond usual duties and picked up @chrishoy from the side of the at Greenhill Stairs after his car went off road."

Around 15 schools in the Highlands and Dumfries and Galloway were closed and conditions are expected to get worse overnight.

The Met Office has issued warnings for up to 20cm of snow for higher ground and ice until late on Friday.

Chief meteorologist Paul Gundersen said: "There's a chance any snow that settles could be disruptive to transport and possibly lead to interruptions to power supplies. Another potential travel problem could be the ice risk overnight.

Glasgow Times:

"Forecasting snow is always challenging and there's often a fine line between whether it will rain or snow in a particular location depending on slight changes in air temperature. Keep an eye on the forecast and warnings for your area for the latest information."

Police searching for a man missing from Hamilton since Wednesday afternoon are worried about the impact of the bad weather.

Joseph Maschinsky, 49, was last seen by his family at their home in Ewart Crescent the South Lanarkshire town at around 2.30pm on Wednesday and said it is unusual for him not to return home.

Inspector Aidan Higgins said: "It is very unusual for Joseph not to return home immediately and with the weather taking a turn for the worse, we are concerned he may have found himself in difficulties."

Snow showers are expected to be less frequent over the weekend but temperatures will remain low.

RAC spokesman Simon Williams said: "Motorists all over the UK are facing very challenging driving conditions from the full array of winter weather.

"Driving in rain, snow and ice is a real danger so the best advice is to drive more slowly, leave far more space behind the car in front than normal, and expect the unexpected.

"If you are unlucky enough to find yourself slipping and sliding on the road, change to a higher gear to gain traction, be gentle with the accelerator and you should keep control. Also, remember to give yourself more time to brake and apply the pressure on the brake steadily. "