Toronto Paramedic Services spokeswoman Kim McKinnon said personnel had treated an unknown number of injuries but declined to provide further detail. Bodies covered by blankets could be seen in the area.
Sunnybrook Health Sciences Centre in Toronto says it has received seven patients from the scene.
Sunnybrook says its emergency department has been locked down as an added precaution, and the centre has activated its Hospital Emergency Operations Centre and is meeting currently to ensure beds are available for the injured.
Const. Caroline de Kloet did not provide details on the suspect’s identity or any charges that might be pending.
The incident took place near the intersections of Yonge Street and Finch Avenue East near 1.30 pm.