Edmonton's mayor says violent attacks overnight in the city that saw a police officer stabbed and several pedestrians run down by a truck were the work of a "lone wolf."
Don Iveson said a 30-year-old male suspect was in custody and being interviewed by police Sunday morning.
"To the best of our knowledge, this was a lone wolf attack," he said at city hall as he urged calm. "It is vital now that we not succumb to hatred, that we not be intimidated by violence.
"Terrorism is about creating panic and about sowing divide and about disrupting people's lives. We can succumb to that or we can rise above it."
It took place over more than four hours, starting with an attack on an officer outside a football game at 8:15 p.m. Saturday night, leading hours later to a multi-car high-speed police chase through downtown that saw four pedestrians run over by the suspect as he twisted and turned his cube van through alleys and cross streets.
It ended when the suspect's truck crashed onto its side, with police handcuffing and hauling him away.
No deaths have been reported. The names of the victims, the suspect, and the nature and severity of their injuries have not been released.
Prime Minister Justin Trudeau condemned the violent events overnight as a "terrorist attack" and a "senseless act of violence."
"Early reports indicate that this is another example of the hate that we must remain ever vigilant against," Trudeau said in a statement.
"We cannot — and will not — let violent extremism take root in our communities."
Police say it began outside Commonwealth Stadium, northeast of downtown, in a game between the CFL's Edmonton Eskimos and Winnipeg Blue Bombers.
It was military appreciation night. Canada's chief of defence staff, Gen. Jonathan Vance, conducted the pregame coin flip and two CF-18 fighter jets did a fly-past before kickoff.
Outside the stadium, a police officer with his marked, flashing cruiser was handling crowd control and security when a speeding white Chevy Malibu rammed through a barrier, sending the officer flying five metres through the air.
The Malibu driver then got out and began stabbing the officer.
"He was stabbed several times and he was able to fend off the attacker even after getting thrown through the air after being struck by the vehicle," said Det. Bob Walsh, president of the Edmonton Police Association.
Surveillance video released by police appears to depict the police officer wrestling with the driver on the ground. At one point, it appears the officer is on top of the driver.
Footage shows them both getting to their feet and the driver running across the street while the officer slowly follows behind him into traffic.
"He followed him for a little bit and radioed ahead to let them (police) know what had happened," said Walsh.
Edmonton police Chief Rod Knecht said an Islamic State flag was found in the front seat of the Malibu.
The manhunt was on. Police set up checkpoints and began stopping cars, leading to a second encounter with the suspect, now driving a U-haul cube van, east of the stadium just after midnight.
Knecht said when the U-haul pulled over for the checkpoint, the driver was confronted after he produced identification linking him to the registered owner of the Malibu.
The U-Haul then sped off toward downtown and Jasper Avenue, the city's main east-west thoroughfare, with multiple police cars in pursuit.
The truck veered into alleys and cross-streets through the downtown amid late-night bar and nightclub goers. Knecht said the truck deliberately hit four pedestrians.
Austin Elgie, manager of The Pint bar, saw the van zoom by with police giving chase.
The van "peeled" into an alley where people were smoking, he said.
"There were like 10 cop cars following him ... It was crazy. It just came around the corner, ripping. I thought at first he was pulling over for the cops coming by, but he was clearly the one they were chasing."
Elgie said the van hit a man who was a bar customer.
"I have a registered nurse on my bar team and I grabbed her and had her look after the guy until the ambulance came.
"He was breathing and we got him in the ambulance and he was still breathing."
The chase came to an end outside the Matrix Hotel, just south of Jasper Avenue, when the van rolled on its side.
Witnesses said they saw the suspect being pulled from the vehicle through the broken windshield and then placed in handcuffs.
Bystander Natalie Pon posted pictures of the U-Haul on its side with a large hole in the windshield.
Knecht said the suspect was known to police, but there was no warning for the attack. Police were to deliver an update later Sunday.
Alberta Premier Rachel Notley called the attacks horrific.
"Hatred has no place in Alberta. It's not who we are. We are in this together and together we are stronger than any form of hate," Notley told reporters at the legislature.
In Regina, Public Safety Minister Ralph Goodale was asked if the suspect had been known to Canada's spy agency.
"The individual apparently had some appearance on a police watch list, but that is a detail of the investigation that the authorities will pursue in the appropriate way. There are no conclusions that can be drawn at this present time," said Goodale.
Walsh said he visited the officer, a 10-year veteran, in hospital.
"He was in good spirits," said Walsh.
He was very shaken up — still a bit in shock. He went through a very traumatic incident. It is something that won't go away today or tomorrow. There will be some side-effects that will traumatize him for a longtime yet to come."
Edmonton police Sgt. Michael Elliott, speaking on behalf of the Alberta Federation of Police Associations, said the public reaction to the attack will be critical.
"We want our communities to come together. When events such as this occur and could potentially create a divide," said Elliott.
"This has happened in Germany, France and England and now it has made it to our doorstep. Only together can we change the tide."
— with files from Andy Blatchford in Ottawa