A dramatic rescue of two teenage girls took place last night after they became stuck on Morston Marshes, near Blakeney, with one suffering symptoms of hyperthermia.

A dramatic rescue of two teenage girls took place on Friday after they became stuck on Morston Marshes, with one suffering symptoms of hyperthermia.

The 14-year-old friends were walking their dogs at about 4pm when they became stuck in the snow and had to be rescued by the Norfolk police helicopter using thermal imaging technology to detect them in the dark.

It is thought the girls, who are believed to be from the Blakeney area, fell down a ditch and then became stuck in the snow, losing their shoes as they attempted to free themselves.

Graeme Kynoch, police air observer who went on the rescue with colleagues Steve Norris and Elliot Macrow, said: 'Luckily they still had mobile phone reception and one of the girls called 999 and spoke to our control room. They were told to huddle close together and that we would come and find them.

'We launched and got to Morston, but the light had gone by then and so we used the thermal imaging camera, and within a couple of minutes we located two bodies with their dogs nearby and our pilot Steve said it was safe to land.'

One of the girls walked to the helicopter, but the other had to be carried because of her injuries.

PC Kynoch, who has been part of the helicopter crew since 1995, said: 'I stayed behind with the two dogs while the girls were taken to Blakeney Point where there was an ambulance waiting. They then came back to get me and we dropped the dogs off with a relative who was waiting at Blakeney before returning to Norwich International.'

The helicopter crew are more used to tracking criminals than rescuing people.

'It is unusual for us; we are not a rescue aircraft but it was easier for us to get to the girls and land, which took about six minutes, than get the RAF to come out or direct a land vehicle to them,' added PC Kynoch.

An ambulance crew treated the girls at the scene before releasing them into the care of their parents.