An air ambulance destined for Orkney on a mercy mission mistakenly flew to Shetland more than 150 miles away.

The plane had been called out to transfer a baby from Orkney to Aberdeen for treatment but went to the wrong islands.

The Scottish Ambulance Service and NHS Grampian has now launched an investigation into the mix-up, which happened last Friday.

One Orkney politician described the incident as "deeply concerning".

A Scottish Ambulance Service spokesman said: "We are aware of an incident on Friday, March 17, where an air ambulance was sent to Shetland instead of Orkney.

"This is an extremely unusual occurrence and we made arrangements for our aircraft to collect the patient from Orkney as soon as we were made aware of the error.

"The patient was transferred safely to hospital in Aberdeen by air. We are working closely with NHS Grampian to establish the circumstances around the initial request."

Orkney MSP Liam McArthur said he had contacted the ambulance service to ensure such a mix-up does not happen again.

He said: "The importance of the air ambulance service to islanders cannot be overstated. All too often it can be the difference between life and death.

"Reports that a flight meant to pick up a patient in Orkney can end up in Shetland are deeply concerning. Fortunately, on this occasion, no harm appears to have come to the young patient involved, but it is imperative that the investigation under way is concluded quickly and any additional safeguards necessary put in place.

"There must be no question of this sort of thing happening again. That is the assurance I have sought and hope to receive from the chief executive of the Scottish Ambulance Service."