A search operation in Tenerife for a missing British teenager has entered its seventh day.

Jay Slater, from Oswaldtwistle in Lancashire, went missing last week after attending a music festival on the Spanish island.

Specialist dog teams have been out searching for the 19-year-old, who has not been heard from since he called a friend on Monday, saying he was lost and needed water.

Spanish police declined to comment when asked on Saturday about reports of a sighting of Mr Slater later on Monday – after the phone call.

His mother Debbie Duncan has issued a direct plea to her son, saying: “We just need you home”.

On Saturday, the sixth day of the search operation, police, rescue dog teams and firefighters resumed combing the mountainous terrain at Rural de Teno National Park – Mr Slater’s last known location.

The apprentice bricklayer’s friends and family have said he had earlier left the group he travelled with in the tourist hotspot of Playa de las Americas, on the south of the island.

After leaving the NRG music festival at Papagayo night club, he got in a car with two men he had met to drive to the national park in north-west Tenerife.

Friday’s efforts were focused on a mountain road in ravine in northern Tenerife, before moving to a valley in the village of Masca.

Dogs, police and mountain rescue workers searched areas including land around the apartment in Masca, which Mr Slater had reportedly travelled to.

The search parties for Mr Slater were reportedly smaller on Saturday compared to previous days. Only a handful of emergency workers were seen in Masca and the surrounding areas.

Firefighters appeared to be doing most of the searching in these areas.

Rescue teams, accompanied by sniffer dogs, set off on a steep gravel track at Rural de Teno Park on Saturday.

Away from the on-the-ground search efforts, the administrator of a Facebook page set up to help find Mr Slater said somebody who was not the 19-year-old had logged in to his Instagram account.

People who had been “hacking” the social media accounts of his family were “sick in the head”, Rachel Louise Harg said.

She also said a fundraising page had been set up to help family and friends staying in Tenerife to search for him. Donations on the page have now exceeded £28,000.

Many members of the community in Oswaldtwistle have expressed concern about Mr Slater’s wellbeing.

The Reverend Matt Smith, from West End Methodist Church, said a service being held on Sunday would be “a chance for the community to come together”.

“It will be a normal service and we will offer our prayers for Jay and give an opportunity for people to leave messages for him and light candles,” he said.

Specialist officers are continuing to support Mr Slater’s family, Lancashire Police said on Saturday.

The force previously said it had offered to assist Spanish police searching for him, but were told their counterparts in Tenerife felt they had enough resources.

Mr Slater was on his first holiday without family and had travelled to attend the festival with two friends.

Lucy Law, thought to have been the last person to speak to him, said he told her in their call that he had missed a bus and decided to walk the 10-hour journey home but was lost, needed water and his phone was on 1% battery.

The Rural de Teno Park is about a 40-minute drive from where Mr Slater and his friends were staying.

A remote and wild national park, it is a world away from Los Cristianos and Playa de las Americas, the party town holiday resorts of the island’s south coast.

Deep ravines and huge daunting mountains make the national park a difficult place for the Spanish search teams to navigate.

• Sunday 16 June – Jay Slater and friends attend final day of the NRG music festival at Papagayo night club in the tourist hotspot of Playa de las Americas

• Monday 17 June – Between 03:00 and 06:00 BST Mr Slater got into a car with two men he had met during the holiday and left Playa de las Americas

• 07:30 – Mr Slater posts a photograph on his Snapchat account showing him at the doorway of a property, tagged with the location Parque Rural de Teno

• Between 08:30 and 09:00 – Mr Slater calls his friend and says he missed a bus back south and was attempting to walk the 10-hour journey

• The call cuts out, with his phone’s last location showing a path in the mountainous Rural de Teno national park, popular with hikers

• Tuesday 18 June – Despite his friends searching the area, no sign of Mr Slater emerges and he does not return to his accommodation

• Local police and mountain rescue teams begin searching and his mother and brother board a flight to Tenerife

• Wednesday 19 June – The Spanish Guardia Civil continue the search using drones, dogs and a helicopter but no trace is found

• The search is briefly moved to the Los Cristianos area in the south of the island due to a potential sighting, but police quickly “discount” that lead and move the search back to the original area

• Thursday 20 June – The Guardia Civil, mountain rescue, firefighters and volunteers return to scour the national park

• Friday 21 June – Lancashire Police confirms it has offered to help the search but says Spanish Police are “satisfied that they have the resources they need”

• Saturday 22 June – Police, rescue dog teams and firefighters continue combing the mountainous terrain at Rural de Teno National Park

• His mother, Debbie Duncan, issues a direct plea to her son, saying: “We just need you home”