British teenager Jay Slater has been missing on the Spanish island of Tenerife since Monday morning.
His mother, a team of mountain rescuers and police are searching for the 19-year-old after he disappeared while holidaying with friends.
In his last phone call to a friend, he said he was lost, in need of water and nearly out of phone battery as he attempted an 11-hour walk back to his accommodation.
Mr Slater, an apprentice bricklayer from Oswaldtwistle near Blackburn in Lancashire, was last seen by his friends at the NRG festival on Sunday.
Here is what we know so far about his last known movements and the search to find him.
A timeline of his last known movements
Sunday afternoon - Mr Slater attends the NRG festival in south Tenerife with a group of friends. Afterwards, he goes to the northwestern mountain village of Masca with two people he met at the festival.
Monday, around 8am - Ofelia Medina Hernandez, the last known person to speak to Mr Slater, tells him the bus is due at 10am when he asks. He sets off walking and she says she later drives past him "walking fast".
Monday, 8.15am - He calls his friend Lucy Law saying he was lost as he attempted to walk from Masca to his accommodation in Los Cristianos in the south.
Monday, 8.50am - His last live location showed as the Rural de Teno park - a mountainous area popular with hikers.
Monday, 9.04am - He is reported missing.
Last phone call - on 1% battery
The last person to speak to Mr Slater was his friend Lucy Law, who says he called her on Monday morning to say he was lost, in need of water, and only had 1% charge on his phone.
During the short phone call, he told her he had missed a bus trying to get back to his holiday accommodation so was attempting to walk instead - a journey that would take 11 hours.
She told the Manchester Evening News someone Mr Slater had met on his night out had driven him back to their apartment in a hire car without him realising how far away it was.
"He's ended up out in the middle of nowhere. Jay was obviously thinking he would be able to get home from there," she told the newspaper.
Mr Slater rang her to say he "didn't know where he was", that he "needed a drink" and had "cut his leg on a cactus", she told the UK Tonight programme on Sky News.
He was without food and water, she added, and had been in a T-shirt and shorts. "It's very warm in the day and very cold at night," she said.
Ms Law said before his phone cut out, he said he had missed a bus trying to get back to his holiday accommodation so was attempting to walk instead - a journey that would take 11 hours.
Questions about why Mr Slater attempted journey on foot
Ms Law said she "managed to find the house" where Mr Slater was last seen.
Two people at the house told her Mr Slater had gone out for a cigarette before going back in and saying he wanted to go home, she added.
"They told me he'd spoken to the next door neighbours and they'd told him there was a bus every 10 minutes back down to Los Cristianos," she said.
"The bus stop was right next to the house. So obviously if he'd gone to get the bus he wouldn't have got lost because it [the stop] was visible from the front door."
The owner of the property where he was last seen, who gave her name as Ophelia, told reporters she saw Mr Slater walk up the road past her property but did not see him again after that - describing the situation as worrying.
The search for Mr Slater
Helicopters, rescue dogs and drones have spent days scouring overgrown terrain, hillsides and rivers.
Police, firefighters and search and rescue teams combed a vast area of land in and around the village of Masca on Friday.
Teams also paid close attention to a river called Barranco Madre del Agua at the bottom of a ravine, where emergency workers carefully picked their way through fallen dead palm trees.
They later moved to other areas, focusing a lot of their resources in an area near Rural de Teno park.
Mr Slater's family has set up a Facebook group to help review aerial images, CCTV, and social media footage in an effort to find him.
A missing person's poster says Mr Slater was last seen wearing a white t-shirt, shorts, trainers, and carrying a black bag.
Read more:
Photos show Tenerife property where teen was last seen
'Living nightmare' hunt for missing British teen
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What are the authorities saying?
The Spanish Civil Guard told UK media it was "doing everything possible" to find Mr Slater.
"A specialist mountain rescue and intervention group called the Greim have been mobilised."
Lancashire Constabulary said it has offered to support Spanish police "if they need any additional resources", but the offer was rejected.
The force added: "They have confirmed that at this time they are satisfied that they have the resources they need, but that offer remains open and they will contact us should that position change."
The Foreign Commonwealth and Development Office (FCDO) said in a statement: "We are supporting the family of a British man who has been reported missing in Spain and are in contact with the local authorities."
What Mr Slater's family have said
Mr Slater's mother Debbie Duncan flew out to Tenerife on Tuesday.
She said: "It's just traumatic and it doesn't feel real. It's just awful, it's horrendous.
"I think he's been taken against his will with what's been said, but it's in the hands of the police."
She said of her son: "He's just a great person who everyone wanted to be with. He's good looking, he's a popular boy."
She added that the police leading the search had been "very good".
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Coronation Street star Vicky Entwistle, best known for her role as Janice Battersby on the soap, is the goddaughter of Mr Slater's grandmother.
She posted on X on Tuesday: "My God Mother's Grandson has gone missing. His mother has flown out 7pm. To join the police search. Hope to God they find him. Please [pray] for him."
Mr Slater's stepfather Andy Watson told The Sun his stepson is "no mug" and "very streetwise", but that he may have lost his bearings while it was dark.
