An elderly woman with dementia has been the victim of a "disgusting" daylight mugging, having her handbag stolen while walking down a suburban street.

The daughter-in-law of the woman is urging people to be aware - this is the second handbag-snatching incident in three months.

Diane Van den Akker was "disgusted" to hear her mother-in-law, who suffers from dementia, was mugged last Friday while walking down Marguerita St.

Therese Shortall lives in the Glenbrae Arvida Retirement facility nearby and often walks to and from the bus stop on her own.

"She doesn't really remember it, which in a sense is a good thing, but she does have pretty bad bruising up her arm," Van den Akker said.

A neighbour reported the incident to Rotorua police, saying two young women pulled over their car before one got out and snatched the handbag off Shortall's arm.

"She's a tiny little thing, with a walking stick," Van den Akker said.

"I just couldn't believe they would do that to someone on purpose."

Van den Akker said when she spoke to the rest home she discovered her mother wasn't the only one to have been approached or robbed.

As reported in the Rotorua Daily Post at the time, two young women stole a handbag from an elderly woman walking on Fenton St in April.

"To be preying on the older people is something else, especially to know this is women.

"I think they're just looking at opportune moments."

She said Shortall couldn't remember the incident but she certainly hadn't mentioned catching the bus again.

"She's finding things really hard at the moment, it's been such a shock, I think her dementia is actually worse."

Shortall told the Rotorua Daily Post it had been difficult having all her cards and her chequebook taken.

Glenbrae Arvida Retirement and Care manager Maria Jay said she had delivered a letter to the residents letting them know what happened.

"There are some sad people out there who do target our elderly and certainly when we delivered the letters, people were already aware and do take precautions."

She said residents were careful not to wearing bags over their shoulders and were particular with the type of wallets they chose.

"It is really sad they have to be so vigilant.

"We are supporting them to live the life they want to live and people are taking advantage of that.

"Our residents will still be catching the bus and going out for walks."

Rotorua police area prevention manager Inspector Brendon Keenan said there had been similar incidents before.

"Anyone that's vulnerable is open to this opportunist-type offending.

"It's not good at all, these are often the people in our community we want to protect the most."

Keenan said it helped for people to travel together but he knew that wasn't always possible.

"It's also important to conceal items, don't make your bag too visible, use pockets or smaller bags."