Gunshots rang out around 8:18 a.m. in the Moka cafe and emergency crews found "quite a scene," said York Regional Police Const. Andy Pattenden.
"The information that we have is that a man arrived here and began shooting," he said.
Maria Voci, 47, and Christopher Desimone, 24, were found dead inside the cafe, located in a strip mall in a busy area of Vaughan. It's not yet known if Voci and Desimone were employees or customers.
The surviving two victims were rushed to hospital, one man with life-threatening injuries. The second man is in stable condition, police said.
Investigators have not said if there were any other customers or employees in the cafe who were not injured.
Police are looking for a suspect they described as a male with darker skin fleeing the scene on Islington Avenue south of Highway 7 in a dark-coloured compact car, heading southbound on Islington Avenue.
There was a heavy police presence in the area throughout the day Wednesday as officers canvassed for witnesses and looked for video surveillance of the incident.
It was busy at the time of the shooting and investigators have spoken with several people who were at the scene when the incident occurred, Pattenden said.
Police are asking for anyone in the area around the time of the shooting to contact homicide investigators.
Hours later, about three kilometres south of the cafe, a vehicle with two people inside was shot three times by an unknown assailant in another vehicle, said Toronto police.
The passengers were unharmed and the suspect fled northbound on Islington Avenue around 11:30 a.m., police said. Officers recovered numerous shell casings from the road.
Police said there is no indication the two shootings are related.
Note to readers: This is a corrected story. A previous version misspelled the name of the cafe.
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