Two baby sisters were seriously ill in hospital last night after an apparent fox attack at their home.
The nine-month-old sisters were savaged while sleeping in their cots on Saturday night.
Officers and paramedics were called to a house in Homerton, east London, at around 10pm to reports that the animal had attacked the girls.
A police source said the fox apparently entered through a door on the ground floor that had been left open for ventilation, before attacking the twins in an upstairs room.
Their four-year-old brother, who was also sleeping upstairs, escaped injury.
Police said the little girls are in a "serious but stable condition" at the Royal London Hospital.
They both suffered arm wounds and one of the girls is believed to have facial injuries.
A Scotland Yard spokesman said: "Police were called at approximately 10pm on Saturday June 5 to an address in Homerton E9 to reports of a fox attack.
"Officers and the London Ambulance Service attended and found two nine-month-old girls with injuries.
"Both babies were taken to an east London hospital where their condition is described as serious but stable."
After the attack, pest controllers set fox traps in the back garden.
Last night, a fox was discovered in one of the devices and was humanely destroyed by a vet early today.
The spokesman said: "Hackney environmental health officers arranged for traps to be set in the rear garden of the address.
"(Last night) a neighbour informed environmental health officers that an animal could be heard in one of the traps.
"Police attended with a local authority pest controller and a fox was indeed found in a trap.
"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."
In 2002, Kent woman Sue Eastwood said her baby boy, Louis, was left injured after a fox crept into their house while she slept.
The 14-week-old suffered bite marks on his head after the animal darted into the sitting room of the house in Dartford.