Police said the suspect, believed to be 30, crashed the vehicle through a barricade and hit the officer at about 8:15 p.m. local time, sending him flying 15 feet into the air and against a police cruiser.
Here is what the Edmonton Police Service is saying about the stabbing of an officer Saturday night and a vehicle that struck four pedestrians.
A 30-year-old man was arrested after the crash; while police are still investigating, they now believe the suspect acted alone in both incidents.
The suspect's vehicle struck the officer, "sending him flying 15 feet through the air", police said.
Knecht said an Islamic State of Iraq and the Levant (ISIL) flag was found in the front seat of the vehicle.
Canadian Police say they are investigating possible acts of terrorism after multiple incidents in the capital city of Alberta province, reported the BBC.
Police launched a manhunt for the suspect.
The chase concluded with the U Haul truck flipping over on Jasper Avenue. The impact sent the officer "flying 15 feet through the air", according to a Police statement.
While the condition of the pedestrians is unknown, the police officer is expected to recover, as his injuries are not critical.
A few hours later, a U-Haul cube van was stopped at an impaired driving checkstop north of downtown. Four people were injured by the van, however, the extent of their injuries was not immediately known.More news: Kane's double help Spurs thrash Huddersfield
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Trudeau said the Royal Canadian Mounted Police and the country's Integrated National Enforcement Team had joined the Edmonton police in its investigation. He also confirmed that an ISIS flag was found in the miscreant's auto.
Austin Elgie, manager of The Pint bar just west of the downtown core, saw the van zoom by with police giving chase.
"Terrorism is about creating panic and disrupting people's lives", he said, adding that Edmontonians would "rise above hatred and division".
Dramatic photos from Global News showed the flipped U-Haul on its side with its windscreen smashed to pieces.
While being chased, the suspect tried to hit pedestrians as he passed by crosswalks and alleyways, Knetch said.
Austin Elgie, manager of The Pint bar just west of the downtown core, said the truck hit a person in the alley outside his establishment.
Police have one man in custody and say they think he acted alone, but they aren't ruling out that others are involved.
The incident began Saturday night outside the Commonwealth Stadium in Edmonton.
Edmonton police believe the two incidents are related.