A large-scale search of rough terrain for missing British teenager Jay Slater is set to begin after Spanish police put out a call for volunteers to help.
On Friday the Guardia Civil formally invited voluntary organisations and members of the public with expertise in difficult conditions to come to northern Tenerife.
Mr Slater, 19, has not been heard from since the morning of 17 June, after he told a a friend he was lost in the mountains and had 1% battery on his phone.
The search will focus on the ravines and trails around the village of Masca in the Rural de Teno national park, and will start from the Mirador de la Cruz de Hilda restaurant at 09:00 BST.
Since the teenager disappeared 12 days ago the Spanish authorities have deployed helicopter crews, specially trained search dogs and drones, but no trace of him has been found.
