Police are looking for the owner of a dog that broke a 74-year-old woman's arm in a terrifying attack.
The victim and another woman were taken to the hospital after being bitten.
The women had stopped to share details after a small traffic crash when the dog appeared and attacked them on White Hart Roundabout in Northolt, West London.
Another person nearby stopped her car during the attack and let the dog into her vehicle, before driving the animal to a Shell petrol garage where it also bit her arm, the Metropolitan Police said.
When officers arrived at the scene, they took control of the dog, reports MyLondon.
Police are now trying to track down the owner of the dog involved in the attack which took place just before 11pm last Thursday.
The elderly victim's son said the dog broke his mum's arm with "a large chunk of her tendons and muscle" removed.
He wrote on Facebook: "The lady concerned is my 74-year-old mother who is stable following the attack.
"The incident occurred following a 'minor collision' of her car and another member of the public's car at the roundabout.
"While inspecting the superficial damage the dog appeared and began to attack my mother for what appears to be five to six minutes, breaking her arm and removing a large chunk of her tendons and muscle.
"She was rushed to hospital and is stable following an operation, but has more scheduled."
He added: "We cannot thank enough the two occupants of the other vehicle involved in the collision who bravely and desperately sought to fight off the dog for many minutes.
"Thank you also to the London Ambulance Service and Metropolitan Police who both attended in significant numbers."
A spokesperson for the Met Police said: "Police were called at 10.54pm on January 26 to White Hart Roundabout, Northolt. Two vehicles had been in a collision.
"As those involved were exchanging details one woman was approached and attacked by a dog, causing injury to her arm. The other people began trying to help her. The dog did not belong to them.
"Another member of the public, seeing the incident, stopped her car and opened the door. The dog got in and she took it to a petrol garage off Yeading Lane, where it bit her arm.
"Police arrived and took control of the dog. It was taken to a police station where efforts to locate the owner are ongoing. The two women's injuries are not life-threatening."
A London Ambulance Service spokesperson confirmed they "treated one patient for significant injuries before taking them to hospital and the other patient, who had minor injuries, made their own way to hospital."
