“We don’t know the cause of the explosion right now,” Toronto police Sgt. Rick Proctor told CP24 at the scene.
Firefighters have since declared the area safe, he said.
Initial reports indicating that a fire also occurred at the business were erroneous, Proctor said.
Preliminary information that two patients had been transported to hospital was caused by a computer glitch, Toronto Paramedic Services said.
One witness described seeing the patient emerge from the building after the explosion.
“A gentleman came out with severe burns – his skin was peeling and there was blood everywhere,” Nima Pakjou said.
Information on the age of the patient was not immediately provided. It was also not immediately clear if he was an employee working at the dispensary.
Pakjou and another witness both described seeing smoke coming out of the roof of the building following the blast.
“The glass literally blew right into the middle of the road – that’s how big the explosion was,” he said.
The incident was cause for concern for one area resident.
“There’s a public school and a daycare centre – what if this happened while the schools were in session,” asked Olga Fowell.
“This has to be the model on why, right now, there should be a raid across the city and shut (the dispensaries) all down,” she said.
The Ontario Fire Marshal has been called in to investigate.