At least 10 people were killed when a man drove a van into a crowd of pedestrians Monday in Toronto, also injuring 15 in Canada's biggest city.
Here are the main facts known so far in what the government is calling a deliberate attack.
At 1:26 pm (17:26 GMT), police received an emergency call reporting pedestrians hit on busy Yongue Street in the center of Toronto.
A white rented van sped along that street or the sidewalk at lunchtime for about half a mile (one kilometre), said police chief Mark Saunders.
At 1:52 pm, a man was arrested near where the van had been left, with its front bumper dented.
Police first said that eight to 10 pedestrians had been hit. They later said the toll was 10 dead and 15 injured, including some in serious or critical condition.
Over a stretch of several hundred meters, the bodies of those who died were covered by orange sheets. Police worked to identify them.
Police identified the van driver as 25-year-old Alek Minassian, from a Toronto suburb. Police said they hoped their interrogation of him would reveal his motive. They said he had no police record.
At the time of his arrest, he was holding some kind of object in his left hand as police squared off with him, according to photos seen on social media.
Police handcuffed the man as he lay on the ground.
"The actions definitely looked deliberate," Police Chief Saunders told journalists. He said the driver was driving on the street as well as the sidewalk.
Ralph Goodale, the minister of public security, added that "on the basis of all available information at the present time, there would appear to be no national security connection to this particular incident."