The mother of nine-month-old twin girls has described her "living nightmare" after her daughters were apparently mauled by a fox as they slept in their cots in east London.

Lola and Isabella Koupparis were attacked at about 2200 BST on Saturday.

A police source said the fox apparently entered the house through an open ground-floor door before attacking the twins in an upstairs room.

Both girls suffered arm injuries and one is thought to have facial injuries.

The twins remain in a serious but stable condition. One of the girls has been transferred from the Royal London Hospital to Great Ormond Street Hospital for further treatment, Barts and The London NHS Trust said.

The girls' mother, Pauline, told BBC London 94.9: "It's a living nightmare.

"It's something I would never have expected to happen - let alone to us and my beautiful girls," she added.

Mrs Koupparis said she heard a noise, described as "a funny cry, not a normal cry", coming from the room where the twins were sleeping.

She added: "It was quite muffled but very pained. I went into the room and I saw some blood in Isabella's cot, I thought she had a nosebleed.

"I put on the light, I saw the fox, it just looked at me and it wasn't even scared of me.

"I started screaming as I realised Lola was also covered in blood."

URBAN FOXES In Britain, foxes were first established in cities such as London and Bristol during the 1940s

Estimates suggest that as many as 10,000 red foxes (Vulpes vulpes) may be living in the London area alone

Foxes principally come into gardens for food and shelter - householders are advised to make sure that foxes get neither on their properties

One concern about foxes is the possibility of the spread of disease to humans and pets

Another concern is 'mange', caused by mites, which can live on foxes

The Royal Society for the Protection of Birds (RSPB) is asking people to report sightings of urban deer and foxes in the first nationwide survey to look at where animals are invading gardens How common are fox attacks?

It is thought the fox may have entered through a door which had been left open because of the warm weather.

The girls' parents, Nick and Pauline, said they had been watching television at the time.

The girls' mother said Lola looked "dreadful"

She added: "One side of her face is beautiful. The other side is like something from a horror movie."

However, she said the baby was "laughing and smiling at people".

"Isabella is in special care, she's not faring as well," she added.

Joe Lobenstein MBE, 83, a former civic mayor of Hackney said he had warned the council about foxes in the area in 1993 and in 2000.

He said: "I wrote that hungry stray foxes are prone to be unpredictable and it seems to me that in a heavily built-up area where there's a considerable mix of very young and very old people the problem should not be taken lightly.

"The council did not act positively and although I very much commiserate with the family that has had such a terrible accident it was the sort of accident which would one day happen and did happen."

A spokesman for the council said there were no indications that the borough had more foxes than other areas of London.

Since the incident pest controllers set fox traps in the back garden of the house. A fox was discovered in one of the traps on Sunday night and was destroyed by a vet.

'Humanely killed'

A Metropolitan Police spokesman said: "Hackney environmental health officers arranged for traps to be set in the rear garden of the address.

"[On Sunday night] a neighbour informed environmental health officers that an animal could be heard in one of the traps.

"A vet was called to establish if it was safe to move the animal. It was determined it was not and the fox was humanely killed by the pest controller at approximately 12.15am.

"The traps will remain in situ for the time being."

John Bryant, a pest control consultant who specialises in foxes, said the attack did not sound like typical fox behaviour.

Mr Bryant, who is an RSPCA Trustee and a member of its Wild Animals Strategy Committee, said: "They will walk into houses, walk round, mess on the bathroom floor and sometimes sleep on the bed if people are not around.

"It just doesn't make any sense to me."

In 2002, mother Sue Eastwood reported that her baby boy, Louis, was injured when a fox crept into their house in Kent while she slept.

The fourteen-week-old suffered bite marks on his head after the animal darted into the sitting room of the house in Dartford.