Alberta's police watchdog is investigating after the RCMP shot and killed an armed man wanted for aggravated assault Sunday night.

The Alberta RCMP were told to be on the lookout for a man wanted for aggravated assault and believed to have a firearm in Onion Lake, Sask., around 4:30 p.m.

The man's cellphone was tracked to a location west of Edmonton, and at approximately 8:30 p.m., police located his vehicle westbound on Highway 16 near Range Road 73.

They attempted to stop him, but the driver kept going and police gave chase, RCMP said.

Mounties deployed a tire deflation device westbound near Entwistle and the vehicle came to a stop at Highway 16 near Range Road 73, police said.

"An interaction occurred between RCMP members and the male suspect, who was the sole occupant of the vehicle, that led to officers firing their service firearms," RCMP said in a release.

The man died on scene, police said. No one else was injured.

The westbound lanes were closed until approximately 3:30 a.m. Monday.