CALGARY -- Alberta's police watchdog is investigating after an officer shot and killed a woman in Calgary.

Police say the officer was responding to a call about 6 a.m. of a suspicious person wandering in and out of several backyards in the city's southeast.

They say a woman in her 30s pepper sprayed the officer, they fought and the officer shot the woman.

The woman was taken in critical condition to hospital, where she died.

The officer, who has been on the force for six years, required medical attention at the scene.

The officer will be placed on a 30-day administrative leave.

Police said in a statement that the officer has the full support of both the police service and union.

The Wednesday morning shooting shows there are no routine calls, the release said.

"When our officers respond to a call from the public in their time of need, we are driven by our common purpose of keeping our community safe," it said.

"At times this means officers find themselves at risk, needing to respond to a dynamic situation that unfolds in a blink of an eye."