Police today issued an appeal for witnesses to the attempted robbery, which happened in the Middleton Park area of the city.
The victim, a 32-year-old woman, was approached by two men while she was walking her two dogs at around 2.50pm on July 20.
A spokesman said: "They made demands for her property and tried to take her bag, before making away."
The first man is described as being of mixed race, around 6ft 2in, slim and in his late teens. He was wearing black tracksuit bottoms with a dark blue hooded top and a scarf across his face.
The second man was also of mixed race, around 5ft 10in and slim. He was wearing dark grey track-suit bottoms and a hooded top.
Anyone with information is asked to contact the non-emergency number 101 or Crimestoppers in confidence on 0800 555 111.
Alternatively, use the online live chat facility via the 'contact us' section of the force website.