Police said the woman was hanging out her washing when her dog began barking at some bushes about 11.15am yesterday .

When she went over to investigate, a woman in her 30s leapt out and attacked her, pushing her to the ground.

The younger woman stuffed a cloth in the victim's mouth to stop her from screaming, but she spat it out. The elderly woman was then threatened, and her hands and feet bound with cloth.

She was pushed under a bush and left there while her attacker went inside and rummaged through her handbag, stealing her car keys, driver's licence and ATM cards.

When the thief fled the house and saw her victim had managed to free herself, she rebound her hands and feet and took off in the victim's car.

Police say the car is a white Mitsubishi Magna with ACT registration plates YVX 826.

AFP forensic officers conducted a scientific examination of the scene and detectives from ACT Policing's Territory Investigation Group are investigating the crime.

Case officer, Constable Dan Williams from the Territory Investigations Group, condemned the attack as particularly callous.

''It's a cowardly attack and the community won't stand for this, and ACT Policing won't stand for it. We won't stand for any of these violent behaviours, but this is particularly callous being an 87-year-old female,'' he said.

The victim was taken to Calvary Hospital and treated for cuts and bruises. Constable Williams said, ''She's holding up well; she's very brave, and she's now surrounded by her friends and family.''

The robber is described as being about 157cm tall, of solid build, and had a fair complexion and blonde hair that was either tied up or about shoulder-length.

She was wearing a fawn-coloured jacket and long, dark-coloured trousers.

Police are keen to speak to anyone who may have seen a person matching the woman's description, particularly around Haig Park in Turner between 10am and 12.30pm yesterday, or who may know the whereabouts of the stolen car.

Contact Crime Stoppers on 1800333 000.