Helicopters joined in the overnight search for the boys

Liam and Callum Clancy, aged nine and 10, and 14-year-old Mark Randals - who is deaf - had last been seen at their homes in Llanaelhaearn, near Pwllheli, at 1915 BST on Thursday, North Wales police said.

Three boys who were missing for 12 hours, have told police they decided to stay out all night as an adventure.

They were found at Trefor, several miles from their home shortly after 0700 BST on Friday.

The boys were wearing summer clothing and were believed to have gone into nearby mountains.

They were spotted walking along the A499 near Trefor, just north of Llanaelhaearn.

Local mountain rescue teams and a police helicopter equipped with a heat-seeking camera, combed the search area.

An RAF rescue helicopter based at Valley, on Anglesey, joined the search area along with members of the RAF Stafford mountain rescue team and search dogs.

The search for the children during the night had been concentrated on a small hill, Moel, where there is an Iron Age fort, and in a wooded area at Pen Llechog on the peninsula.

Superintendent Gareth Pritchard, of North Wales Police, said: "There was immense concern for the boys, especially since last night was colder than it has been for a number of nights.

"The family is extremely relieved to have them back safe."