A pensioner, 93, suffered a broken hip after being attacked near the Point in cmk on Tuesday.
It happened around3.20pm when the woman was pushed to the ground as she waited at a bus shelter. She was taken to hospital where she had surgery on the hip.
Police are now appealing for witnesses to help find the offender.
The offender is described as a white woman in her 40s, around 4ft 10ins or 4ft 11ins tall and a small build.
She was dressed in black leggings, a black top, black baseball cap, wearing dark glasses and was pulling a large shopping trolley.
Det Constable Scott Dempsey, of Force CID at Milton Keynes police station, said: “This was a nasty assault on an elderly lady who was left with a broken hip.
“We are appealing for anyone who may have seen this incident to call 101.
“We are particularly eager to speak to two unidentified men who reportedly helped the victim after the assault.”
If you have any information relating to this case, please call 101 quoting reference ‘43180194097’, or contact Crimestoppers anonymously