Officials are currently asking for witnesses to come forward.
Toronto police confirmed Monday evening that the suspect in custody was 25-year-old Alek Minassian and Canadian broadcaster CBC reported that he was not associated with any organized terrorist group. Reuters reports, however, that a US security source revealed that terrorism is the leading theory regarding the attack.
Toronto Police Chief Mark Saunders released a statement late Monday saying that based on witness testimonies it's "very clear [that] actions definitely looked deliberate" and that police did not have "anything on our files" regarding Minassian. Police have not yet been able to determine a motive.
The incident occurred some 30 kilometers from the Toronto city center, where the G7 foreign ministers had a meeting on Monday.
"Reports were that a white van mounted the curb, drove down the sidewalk at southbound Yonge, south of Finch, and struck eight to 10 people possibly, the numbers aren't confirmed yet," Gary Long, a police spokesperson, told Canadian broadcaster Global News prior to the latest update.
Police stopped the van and arrested the driver shortly after it sped away from the scene of the crash. The video of the alleged driver's detention has been circulating on social media platforms.
Videos and photos of the aftermath of the incident have emerged on the internet.
Internet users have also allegedly uploaded photos of the truck.
In a separate tweet, police said that a shooting occurred near Dundas and Chestnut. It is not immediately clear whether the two incidents are related. Police later said there had been no shooting in the area.