A 63-year-old woman remains in a critical condition after being attacked in Hayes while walking home from a friend's house.
It is believed Valerie Dancer, was walking home from visiting a friend when she was robbed in the underpass under the A312 Hayes bypass, in Carlyon Road, at about 2.45pm yesterday (Tues).
A member of the public called the police to report the incident and when they arrived with the London Ambulance Service, the victim, who lives nearby, was found with head injuries.
She was taken to Charing Cross Hospital by air ambulance where she remains in a critical but stable conditiom.
The suspect is described as a black teenager wearing dark clothing. Following the attack he ran off under the underpass towards Yeading Lane, Hayes.
The victim's beige leather handbag and her black 'Radley' purse were stolen together with other contents of her handbag.
The officer leading the investigation DI Mark Brookes said: "Valerie's family are distraught following this appalling attack and I would appeal to anyone who witnessed what took place or has any information to contact us as soon as possible.'
Anyone with information should contact the Priority Crime Unit at Hillingdon on 0208 246 1445 or, if you wish to remain anonymous call Crimestoppers on 0800 555 111.