The family of missing teenager Liam Smith say they continue to hope he will be found, five weeks on from his disappearance after boarding a bus.

Land and air searches have been carried out for the 16-year-old from Aberdeen, who was last seen at the bus station on Saturday November 17.

He is thought to have got off a Banchory-bound bus at Crathes, but specialist teams have found no trace of the 6ft 4in schoolboy.

His mother Alix Smith said in a statement: "It is now five weeks since we last saw Liam and the prospect of Christmas without him is a really difficult situation for us to face.

"We understand the public's interest and we really do appreciate the support everyone has given by sharing the posts and putting up posters.

"Police officers have been out searching the areas that Liam was last seen every single day since we reported him missing and we are truly grateful for everyone's perseverance in trying to locate him.

"We continue to hope that Liam will be found."

Liam was captured on CCTV boarding a 202 Stagecoach bus for Deeside at 1.11pm. He bought a ticket for Raemoir Road in Banchory but a fellow passenger reported that he got off in the Crathes area.

Searches have been carried out on the Crathes Castle estate and in fields and woodland around the A93. Divers have scanned the River Dee and helicopter crews have surveyed the wider area.

Police say they have had an "overwhelming" response to appeals and have followed up more than 200 reported sightings of Liam.

Chief inspector Martin Mackay said: "Our inquiries still suggest he would have travelled to the Crathes area. We urge residents, particularly in this area, to remain vigilant and report anything unusual to police.

"Intensive searches remain ongoing and will continue with the exception of Christmas Day.

"We know that many people have offered to assist with searches, however we carry out these operations in a highly specialised, methodical way with officers who are trained and experienced.

"We have a plan in place to ensure that all the challenging land we need to cover is searched effectively with the use of the required specialist resources.

"The public in the North East and particularly the Banchory and Crathes communities have been incredibly supportive and we are very grateful for the assistance and support that has been provided."

Liam is described as white, of slim build, with short brown hair.

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

Anyone with information should contact police on 101 quoting reference number 1302 of November 18.