WATCH: Cops in Crathes to find teen

Police officers looking for an Aberdeen teenager who disappeared from the Granite City say CCTV was not working on board a bus the 16-year-old was travelling on towards Banchory a week ago.

The technical issue is complicating a desperate search for Liam who investigators say did not take his mobile phone or even a jacket with him.

Police Scotland's focusing its efforts in the Crathes area of Aberdeenshire after an eyewitness on the same bus at the centre of the probe provided information.

Around 100-telephone calls have come into cops scouring the North East in what officials are calling a "high risk" missing person investigation.

A press conference took place on Friday afternoon to update Northsound News on the progress of ongoing work to reunite Liam with his family.

His mum Alix Smith said: "As each day passes we are becoming more and more desperate to find Liam.

"We are literally clinging to the hope that he is out there somewhere taking shelter.

"Not knowing where Liam is, is just so painful for us and we just want to find him safe.

"Thank you to everyone who has shared the social media appeals, to those people who have phoned the police with potential sightings of Liam, and to the many comments and kind words that have been posted.

"We are really grateful for all of the help and it really does bring us comfort to know that so many people are thinking of Liam and are trying to help us find him.

"He is not in trouble - we just want him home."

A police helicopter, and the force's tracker dogs have been involved in the operation to locate Liam.

Members of the constabulary's marine and dive unit entered the River Dee on Friday morning near to Banchory Lodge Hotel and kayaked towards Aberdeen as part of search activity.

WATCH: Football legend Alex McLeish issues personal video appeal to help find Liam: