Police are relying on a “boots on the ground” approach as they comb challenging terrain in the search for a teenager missing for two weeks.

Liam Smith, 16, was last captured on CCTV at Union Square in Aberdeen shortly before he boarded the 202 1.15pm Stagecoach bus on Saturday November 17, which would have taken him in the direction of Banchory.

It is believed he got off the bus at Crathes and a subsequent credible sighting of him at Crathes Estate that afternoon has led police to focus their search on that area.

Officers said they have used every available resource at their disposal over the past two weeks, including the search helicopter, dog unit, dive unit and specialist police search advisers (Polsa).

Liam Smith
Police issued CCTV images of Liam Smith at McDonalds on Union Street at 12.28pm on Saturday November 17 (Police Scotland/PA)

Chief Inspector Martin Mackay said: “As we enter more challenging terrain every day we are now relying on a ‘boots on the ground’ approach to ensure dense wooded areas are properly checked.

“Many areas have also become flooded due to the wet weather so we are also deploying dive units to assist.

“There is no denying this is a difficult operation and we continue to review our options with every day that passes.

“Two weeks is a long time for any family to be without their son and we continue to keep in contact with Liam’s family. Your comments and words of comfort are much appreciated by everyone involved.

“I would also like to thank the members of the public who have been leaving food and home-bakes for our officers who are searching out at Crathes – we have been shown incredible kindness by the local community.”

Liam is described as white, around 6ft 4in and of slim build.

He has short brown hair and walks with a distinctive gait and when last seen he was carrying a camouflage North Face rucksack and was wearing Nike Air Max trainers.

He bought Lucozade, Jaffa Cakes and Dairy Milk at Sainsbury’s before he left Aberdeen.

Anyone with information can contact Police on 101 quoting reference number 1302 of November 18.