Canadian police charged a Somali refugee with five counts of attempted murder on Sunday after they said he stabbed a police officer and ran down several pedestrians with a car in Edmonton, Alberta, in what officials called an act of terrorism.
The suspect, a 30-year-old man whom police did not identify, had been investigated two years ago for promoting extremist ideology but not deemed a threat, the Royal Canadian Mounted Police said.
At around 8:15 p.m. local time on Saturday, an Edmonton police officer was working traffic control duties at a Canadian Football League game between the Edmonton Eskimos and Winnipeg Blue Bombers.
The officer was patrolling a road southwest of the Commonwealth football stadium. At that time, a male driving a white Chevrolet Malibu crashed through the traffic barricades that were separating vehicles from pedestrians at high speed.
The officer was hit and went flying 15 feet through the air, the Edmonton Police Service (EPS) said in a statement.
A male, believed to be 30 years of age, got out of his vehicle and began stabbing the officer with a knife. The attacker then fled, and the officer was taken to hospital.
Later on Saturday just before midnight, a U Haul truck was pulled over on Wayne Gretzky Drive and 112 Avenue in Edmonton. An officer asked to see the driver's license and recognized the name as being similar to the registered owner of the Chevy Malibu involved in the earlier incident.
The truck driver then immediately fled the scene, but police officers pursued it as the driver deliberately attempted to hit pedestrians. The EPS said four civilians were hit by the truck and taken to hospital with multiple injuries.
The U-Haul truck eventually flipped over, and the driver was taken into police custody.
Police believe the two incidents are related and said they are being investigated as "acts of terrorism."
"Currently, we believe this is an individual who acted alone, although the investigation is in its early stages," EPS Chief Rod Knecht, said in a statement on Sunday.
"We are urging all Edmontonians to be vigilant and aware of their surroundings. Please contact police immediately if you see or hear anything out of the ordinary or unusual."
—Reuters contributed to this report.