Police are looking for a man who attacked and groped one woman and may have also done the same to three others in downtown Winnipeg.

At around 5:20 p.m. on Tuesday a 46-year-old woman witnessed a man performing an indecent act around the 300 block of Portage Avenue, police said.

The woman said she was going to call the cops and then the man assaulted her, police said.

"She made it very clear she was going to call police," said Const. Jason Michalyshen, adding the suspect then confronted her.

The woman fell to the ground, was assaulted again and was later treated for minor injuries.

The man fled but police said they started to receive reports of more indecent acts in the area.

A 27-year-old woman was groped and the man once again fled, Michalyshen said.

"We are aware of potentially two other incidents where females were confronted and approached inappropriately," he added.

Members of the police sex crimes unit are investigating and have released images from surveillance footage.

Multiple women witnessed an indecent act in downtown Winnipeg and one was assaulted. The man seen in this photo is wanted for questioning by police. (Winnipeg Police Service)

Michalyshen said it's important the public remains vigilant because there is an unidentified suspect "who is obviously confronting females in an inappropriate fashion, not only performing indecent acts but also assaulting and potentially sexually assaulting."

If someone approaches you inappropriately, it's important to remove yourself, get to a public space, call for help, draw attention to yourself and call police immediately, he said.

The man was described as about six feet tall and between 20 and 25 years old. He had short black hair, a heart-shaped face and a skinny build. He was wearing a white shirt, black shorts, white running shoes and a baseball cap.

Anyone with information is asked to call police at 204-986-6245 or Crime Stoppers at 204-786-8477.