The search for an Aberdeen 16-year-old now missing two weeks has entered a "boots on the ground" phase.

Liam Smith caught the 202 Stagecoach bus from Aberdeen on 17 November and is thought to have got off at Crathes.

Police said a "subsequent credible sighting" of him in the Crathes Estate area that afternoon had offered further information to lead searches.

Search teams - hampered by bad weather - are now entering "challenging terrain" including dense woodland.

Ch Insp Martin Mackay said: "Over the past two weeks we have had assistance from every available resource at Police Scotland's disposal including the search helicopter, dog unit, dive unit and specialist police search advisers.

"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."

'Incredible kindness'

He added: "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."

When last seen, Liam - who is 6ft 4in tall - was wearing a dark top and blue jeans. He had a camouflage backpack.

He did not have a mobile phone with him.

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

More than 100 reported sightings have been eliminated.