RAF spokesman Flt Lt Curly Crawford says everybody is safe. Video courtesy of Stuart McInnes - www.sleepmonster.com
Hundreds of people taking part in a run in the Lake District near Keswick have been stranded by flooding and torrential rain.
The runners were taking part in the Original Mountain Marathon (OMM) run when they were overcome by the weather.
Honister Slate Mine manager Mark Weir said he was sheltering 300 of them and some were suffering from hypothermia.
Mountain rescue teams have dealt with 11 casualties and say they have no idea whether any more are stranded.
Cumbria Police said competitors spending the night on the mountain were mainly seasoned mountaineers, and were expected to be carrying suitable equipment to cope with adverse weather.
The Environment Agency said rainfall overnight should not be as heavy as had been expected.
About 12 people have been taken to hospital with hypothermia and minor injuries, Northwest Ambulance Service said.
The Mary Hewetson Cottage Hospital, in Keswick, said people had been admitted suffering from hypothermia and minor injuries.
The casualties have since been transferred for treatment to the Cumberland Infirmary, Carlisle, and West Cumberland Hospital, Whitehaven.
About 400 people are understood to be sheltering at Gatesgarth Farm.
Mike Parsons, brother of the marathon's organiser, Jen Longbottom, said the site had been the planned campsite but wet and windy conditions had forced runners to shelter in the barn.
"In 40 years this is the worst weather we've ever had," he said.
A further 78 runners are sheltering at the Glaramara Centre and about 80 at the Cockermouth Sheep and Wool Centre.
Runner Max Folkett on the conditions during the race
A reception centre offering shelter has been set up by Cumbria County Council at Cockermouth School.
Mr Weir said he believed that between 1,500 and 2,000 people had been taking part in the race.
Organisers had "little choice" but to abandon the race around midday after the weather deteriorated, according to the event's official website.
"Race director Jen Longbottom made the decision just before midday after several hours of torrential rain had resulted in extreme conditions on the mountain and severe flooding," it stated.
However, the website said abandoning the marathon was "easier said than done" because thousands of competitors were scattered across the hills and communication was difficult.
Cumbria police said senior officers were assessing the situation, but added it was currently too windy to use an RAF helicopter to assist in rescue efforts.
Honister Slate Mine is at the top of one of England's steepest mountain passes in the Borrowdale Valley, rising to some 2,000ft in height (610m).
Since Thursday, more than 1ft (40cm) of rain has fallen there, according to the Environment Agency.
Mr Weir said the race should have been called off.
"Now we've got several hundred, into the thousand, stranded, cold, tired, some hypothermic," he said.
"We've overwhelmed the emergency services - the poor mountain rescue are out trying to find people on the side of the mountain, in the dark. It's just a bizarre day."
Shane Ohly, who completed the run, said: "The weather was very bad; gale force winds and torrential rain. However, the event is for experienced fell runners and everyone should have been able to cope.
"The Original Mountain Marathon is one of the best organised events of its type and I am sure the organisers will be doing everything they can," he said.
Another run participant, Lewis Peattie, said he and his teammate were lucky to get out when they did.
"We had difficulty getting down due to streams becoming fast torrents of water and 'waterfalls' springing out of nowhere," he said.
Will Creek, who was due to take part in the race, told the BBC that he had pulled out because of the bad weather conditions.
"I looked at the weather forecast and took the view it was too treacherous for my wife and I to take part. I just thought it was too dangerous," he said.
Ian Boorman, of the Glaramara Centre in Seatoller, at the bottom of the Borrowdale Valley, said his centre had taken in 78 runners for the night.
Most had basic supplies with them and staff at the centre had given them hot drinks and dry clothes, he said.
"They're in good spirits," he added.
Police advised drivers not to travel to the region, and many of the main roads through the Lake District have been closed.
According to the website the run was founded in 1968 and was the "originator of the two-day mountain marathon type event".
It involves teams of two, carrying all clothing, equipment, tent, sleeping bag, and their food for 36 hours, during the run. They must also navigate their own route and camp out overnight.
The website goes on to say that the OMM is "the premier UK event to test teamwork, self-reliance, endurance, outdoor and navigational skills. The reputation of the event is worldwide and every year we have entrants from between 12-14 countries."
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