More than 50 firefighters remain at the scene of a large wildfire in the Highlands for a second day as residents are being advised to keep windows and doors shut.

Six fire engines and specialist resources are in attendance at the huge blaze on Ben Bhraggie near Golspie in Sutherland as they work to extinguish the flames.

Reassurance visits have also been carried out to nearby homes and fire crews are working to protect the community and property from harm.

The Scottish Fire and Rescue service also confirmed a helicopter is now on site, operated by Inverness-based PDG Aviation Services, with plans to waterbomb the area.

The alarm was first raised at 12.04am on Saturday when the wildfire broke on a tree plantation on the hillside.

Firefighters worked through the early hours of Saturday as the blaze engulfed the main power lines for the far north of Scotland.

Throughout Saturday, dozens remained on the site using water bowsers, beaters and knapsack sprayers to try to bring the flames under control.

Group Manager Billy McLintock was the officer in charge of the incident overnight into Sunday.

He said: "This remains a complex and challenging incident for crews on the ground and it is likely that we will remain on the scene for some time.

"Crews and partners worked throughout the night on Ben Bhraggie, and during this time our crews and Operations Control have been in regular contact with nearby residents.

"We would advise nearby residents to keep windows and doors closed due to smoke, and contact us should they have any concerns.

"I would once again like to thank the wider community for their ongoing support, the hard work of our partners, and the crews on the ground for their tireless efforts."

Elisabeth Smart, public health consultant for NHS Highland, added: "The public being are advised to obey all instructions from essential services, to continue to keep away from the area and site and to check the Scottish Fire and Rescue Service website for updates.

"The public should keep their windows and doors closed and if there is visible smoke they should remain indoors except for essential travel.

"Anyone exposed to the smoke who develops irritation to the air passages, skin, eyes or respiratory symptoms (coughing, wheezing and breathlessness) or any other unusual symptoms should contact NHS 24 on 111 in the first instance.​

"Individuals with heart or lung diseases such as asthma should ensure they have access to their medication especially inhalers and seek medical advice if their symptoms worsen."

The fire service does not have an exact size of the wildfire at present, but the latest estimate was around 3km by 2km.