The province's Special Investigations Unit has been called in after a woman was shot dead, allegedly by police, at a home near Yonge and Finch on Friday morning.

Officers were responding to a call about a woman allegedly threatening to kill her mother at a bungalow on Wedgewood Drive shortly after 10 a.m., Toronto police say.

SIU spokesperson Jasbir Brar identified the victim as Sylvia Klibingaitis, 52.

She allegedly lunged with a knife at an officer who fired three shots. The SIU would only say that a "police firearm was discharged at least once."

"Unfortunately we've had a serious incident here. It's a matter that falls under the jurisdiction of the SIU. They have invoked their mandate and because of those regulations, I can't comment on the details of the incident," Toronto police Insp. Doug Quan said.

The woman was taken to Sunnybrook Hospital, where she was pronounced dead.

Few other details were immediately available, but one man who lives in the area said the victim was earlier threatening her mother with a knife. That hasn't been confirmed.

"The woman was shot by the police," said neighbour Nestor Arellano.  "They said that she was weilding a knife in the street.  Apparently she was threatening her mom, that was the news that I gathered."

The SIU is now at the scene. The arm’s length agency investigates police where there has been death, serious injury or allegations of sexual assault.

Seven investigators and three forensic investigators have been assigned to the case.

If you saw anything, call the SIU 1-800-787-8529 or 416-622-0748.