A 30-year-old Canadian is in custody after a police officer was hit by a car then "viciously stabbed" and hours later four pedestrians were "deliberately struck" by a fleeing U-Haul truck Saturday night in Edmonton, Alberta, according to the Edmonton Police Service.

Police say the incidents "may be related" and are investigating both as acts of terrorism.

It began around 8:15 p.m. local time outside a football game between the Edmonton Eskimos and Winnipeg Blue Bombers. It was Military Appreciation Night at the stadium and a senior member of the Canadian Armed Forces conducted the pregame coin flip, while CF-18 fighter jets did a fly-over before kickoff, reports The Associated Press.

An Edmonton Police Service officer was working traffic control behind a barricade.

"Suddenly and without notice and at a high rate of speed a male driving a white Chevrolet Malibu crashed through the traffic barricades that were separating vehicles from pedestrians," said Edmonton Police Service Chief Rod Knecht in an early morning press conference. The car hit the officer, sending him 15 feet into the air, and the driver jumped out stabbing "the officer several times before fleeing the scene on foot."

An ISIS flag was found on the front seat of the vehicle, according to Knecht.

As for the officer's condition, "He is obviously injured but it is not critical," Knecht said.

Then just before midnight, a U-Haul was pulled over elsewhere in Edmonton and the officer recognized the name on the license as "being similar" to the registered owner of the Chevy Malibu, according to police.

The U-Haul fled the scene and as officers gave chase, "the U-Haul truck deliberately attempted to hit pedestrians in crosswalks and alleys," Knecht said. Four pedestrians were hit and have been hospitalized "with multiple injuries."

The pursuit ended when the U-Haul flipped and the driver, an Edmonton man, was placed in police custody.

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