The pensioner ran after the man, but could not keep up with him. Det Con Colette Kelleher, of Greater Manchester Police, said the woman had been left "extremely shaken".

"This was a shocking attack on a woman who is particularly vulnerable because of her age and her disabilities," she said.

A couple saw the man running away and found the pensioner's purse, but cash had been taken from it.

The robber was white, between 5ft 10ins and 6ft tall and slim. He was wearing a dark jacket and hat.

Det Con Kelleher said: "There were quite a few people in the area at the time and I'm appealing to them to get in touch if they saw the incident or if they saw the offender before he struck.

"I would also ask people to be on the look-out for this offender and report any sightings of anyone acting suspiciously in the area. I don't want people to be unduly frightened, but I'd advise people, especially elderly people, to be extra vigilant."