A holidaymaker told how he helped to save a teenage boy who was being dragged out to sea after falling from rocks on the Jurassic Coast.

Coastguards said the boy was airlifted to hospital after suffering neck and back injuries in a fall at Lulworth Cove which led to him going into the water.

It is the fourth time in less than a week the Coastguard helicopter has been scrambled to rescue people in distress on the Purbeck coast.

Paul Chambers, 54, and Lisa Bryant, 45, from Reading, were wandering along the rocks at Lulworth Cove on Thursday when Mr Chambers spotted a teenager in distress in the water.

Mr Chambers said: “I spotted something out at sea then looked closer and thought there is someone out there, something isn’t right they’re too far out, then we heard him scream for help.”

Mr Chambers climbed across the rocks to get closer, and managed to drag the teenager onto the rocks.

He said: “He couldn’t swim – if he didn’t have the rucksack he would have drowned, it was buoyancy for him.”

Mr Chambers was assisted by a man who called the coastguards at around 12.15pm.

A Coastguard rescue helicopter from Lee-on-Solent attended the scene, along with Lulworth Coastguard Rescue Team and Weymouth Lifeboat.

It is understood that the teenager was exploring the area when he decided to venture further out on the rocks.

It is the fourth time that the Coastguard helicopter has been called to Dorset's coast this week. On Sunday afternoon, crews were called to four separate incidents at Durdle Door in which two men were airlifted to hospital. On Thursday, a man was airlifted to safety after getting stuck on a cliff in Swanage.

Speaking about the rescue of the teenager, a spokesman for the UK Coastguard said: "A person was reported to be in the water.

"He was pulled to the shore and was then airlifted away by the Coastguard helicopter.

"Weymouth's inshore lifeboat was tasked to assist and did a sweep of the area to see if there were any other casualties."

The helicopter flew the teen to Dorchester Rugby Ground where Wyke Coastguard Rescue had prepared the ground for landing.

A spokesman for Wyke Coastguard said: "The National Maritime Operations Centre had tasked the initial response team to assist Rescue 175, who were inbound from the Lulworth area, carrying a teenage casualty who had fallen and was being treated for suspected spinal injuries."

The teenager was taken by ambulance to Dorset County Hospital for treatment.

James Weld of the Lulworth Estate has warned visitors to avoid the 'delicate cliffs' and has asked them to 'respect the coastline.'

He said: “We urge all visitors to Lulworth to respect this coastline, avoid the delicate cliffs and to heed the safety advice provided. Enjoy your visit to this beautiful area but please don’t put yourself, or the emergency services tasked with keeping us all safe, at unnecessary risk. Our thanks go out, again, to the local coastguard teams, the RNLI and emergency services for their invaluable assistance.”