TORONTO -- The province’s Special Investigations Unit (SIU) is investigating after a man was injured in a police-involved shooting in St. Catharines Tuesday afternoon.

Niagara police said they were called to the area of Rykert and Edith streets at approximately 4:30 p.m. to a report of a male armed with a knife.

When officers arrived on scene, there was an altercation between police and the male. As a result, the 56-year-old man was shot and transported to hospital with life-threatening injuries, police said.

“At this time the SIU has invoked their mandate and they are conducting an investigation,” Phil Gavin, media relations officer with Niagara Police said.

The SIU is an arm’s length agency that is called in to investigate any incident involving police and a member of the public that results in death, serious injury, or an allegation of sexual assault.