Calgary police are investigating the city's third attack against women this month.

Just after 10 p.m. MT last night, a 30-year-old woman was in the alley behind Erin Grove Place S.E. when a man came up from behind and grabbed her.

"The victim was not groped," police spokesman Kevin Brookwell said.

"She was aware of somebody behind her. She felt a hand being placed on her hip. She took immediate action, as best described as a reverse kick, making contact with the suspect. When she turned, the suspect had already turned and was already running away."

The suspect is described as a Caucasian male, approximately 25-years-old.

He has a slim build and was wearing a black hoodie and grey pants.

Police say the incident is similar to two other recent attacks in the Erin Woods community.

On June 7, a woman was groped while working in her garden in a back alley.

And on Tuesday, a 49-year-old woman was jogging in a park near Erin Meadows Green, when she was attacked and groped from behind.

Duty Insp. Paul Malchow says in all three cases, the suspect description is the same.

“It is concerning. we're just fortunate when he's challenged this individual flees, but we're always concerned the attacks might escalate in nature. So, we're putting a strong effort into capturing this individual.”

Police are reminding women to be vigilant about personal safety when out alone.