The shocking moment a suspected terrorist with an Islamic State group flag mowed down a Canadian police officer in a car before getting out to stab him several times was caught on surveillance camera.

Canadian police said early Sunday that an attack on an officer outside a football game and a high-speed chase of a U-Haul that left four people injured in the Western city of Edmonton, Alberta, are being investigated as acts of terrorism.

Edmonton Police Chief Rod Knecht said that officers have one person in custody and think he acted alone, but are not ruling out that others may be involved.

The chaos began outside a Canadian Football League game where the Edmonton Eskimos were hosting Winnipeg on Canadian Forces Appreciation Night on Saturday night at the Commonwealth Stadium. Police say a white Chevrolet Malibu rammed a traffic control barricade and sent an officer flying into the air 15 feet.

Knecht said the driver, believed to be 30 years old, then got out and attacked the officer with a knife before fleeing on foot.

Surveillance footage from the scene first shows the officer standing behind a barricade when the white vehicle runs him down. The driver of the Malibu then gets out and begins attacking the officer on the ground before fleeing the scene.

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The shocking moment a suspected terrorist with an Islamic State group flag mowed down a Canadian police officer (circled above) in a car before getting out to stab him several times was caught on surveillance camera

Police say a white Chevrolet Malibu rammed a traffic control barricade and sent an officer flying 15 feet into the air (circled above) in Edmonton on Saturday night

Edmonton Police Chief Rod Knecht said the driver (circled above), believed to be 30 years old, then got out and attacked the officer with a knife

The suspect then fled on foot after the vicious attack on the officer (circled above). Hours later the same man was caught driving a U-Haul van into pedestrians in the city

Knecht said that officers have one person in custody and think he acted alone, but are not ruling out that others may be involved. The suspect crashed the U-Haul (scene above) on its side after running people down while driving it

The officer was taken to a hospital and treated for non-life threatening injuries while a manhunt was launched for the suspect.

TIMELINE OF ATTACKS First attack happened when an Edmonton Police Service special duty member was stabbed by a man who had crashed a car into a police barricade outside the Commonwealth Stadium at 8.15pm

Police said the suspect then fled on foot

An ISIS flag was found inside the car

Around 11.30pm a U-Haul van sped through downtown streets and was being chased by cops

U-Haul crashed on its side and driver was arrested; his name has not been released

Police say the two incidents are believed to be related and they are being investigated as acts of terrorism Advertisement

A few hours later, a U-Haul van was stopped at an impaired driving check stop north of downtown on Wayne Gretzky Drive.

Knecht said the name of the driver was close to the name of the registered owner of the car that hit the officer.

He said the U-Haul then sped off toward downtown with police in pursuit.

Police say the U-Haul intentionally swerved at pedestrians at crosswalks throughout the chase.

Four people were injured by the van, but the extent of their injuries was not immediately known.

The van eventually rolled near a downtown hotel and a suspect was arrested.

Knecht said he didn't know the extent of pedestrian injuries.

He also said an Islamic State group flag was found in the front seat of the Malibu and seized as evidence.

The chaos began outside a Canadian Football League game Saturday night when the white Malibu rammed a traffic control barricade and sent the police officer flying 15 feet into the air (scene above)

Knecht said an Islamic State group flag was found in the front seat of the car and seized as evidence (scene above)

In a statement, Knect said: 'We ask that our citizens remain vigilant and observant of their surroundings, and contact police should they notice any other unusual activities around the city.'

Knecht said the man was known to police, but did not release his name.

'It is believed at this time that these two incidents are related,' he said.

'It was determined that these incidents are being investigated as acts of terrorism.'

Knecht said Edmonton police are working with the Royal Canadian Mounted Police's National Security Enforcement Team and other Canadian security agencies.

Prime Minister Justin Trudeau issued the following statement after a terrorist attack in Edmonton:

Knecht said they arrested the driver and the man was known to police. His name has not been released (scene above)

The two incidents are believed to be related and they are being investigated as acts of terrorism (scene above)

'The Government of Canada and Canadians stand with the people of Edmonton after the terrorist attack on Saturday that sent an Edmonton Police Service officer to hospital and injured a number of innocent people who were out to cheer on their football team and to enjoy an evening in their city.

'I am deeply concerned and outraged by this tragedy.

'Our thoughts are with those injured, their family and friends, and all those affected by this senseless act of violence.

'I am also grateful for the first responders who were there on the scene, and the enforcement authorities who have been working through the night to make sure that everybody in Edmonton and Alberta is safe and secure.

'Police officers put themselves at great personal risk every single day on our behalf, and this attack is a stark reminder of the sacrifices they make for the public good.

'While the investigation continues, early reports indicate that this is another example of the hate that we must remain ever vigilant against.

'The RCMP and the Edmonton Police Service, through the Integrated National Enforcement Team, are working closely together to bring those involved to justice.

Knecht said Edmonton police are working with the Royal Canadian Mounted Police's National Security Enforcement Team and other Canadian security agencies during the investigation (scene above on Sunday)

Of the incident, Prime Minister Justin Trudeau said: 'I am deeply concerned and outraged by this tragedy. Our thoughts are with those injured, their family and friends, and all those affected by this senseless act of violence' (scene above on Sunday)

Trudeau added: 'We cannot – and will not – let violent extremism take root in our communities. We know that Canada's strength comes from our diversity, and we will not be cowed by those who seek to divide us or promote fear' (scene above on Sunday)

Rachel Notley, the Premier of Alberta and Leader of Alberta's NDP, tweeted the above statement about the incident

'We cannot – and will not – let violent extremism take root in our communities. We know that Canada's strength comes from our diversity, and we will not be cowed by those who seek to divide us or promote fear. Edmonton is a strong and resilient city, and I am confident that its citizens will support one another to overcome this tragic event.'

He also tweeted: 'We'll never let violent extremism win. Canadians stand with the injured in Edmonton'

Rachel Notley, the Premier of Alberta and Leader of Alberta's NDP, tweeted: 'Our thoughts are with @edmontonpolice member injured on duty tonight & hoping for a speedy recovery. Grateful for our first responders.'

The U.S. Department of Homeland Security is monitoring the situations in Edmonton and Marseille; there has been no change to U.S. security posture.

Anyone with information about these violent incidents are urged to contact the EPS at 780-423-4567 or #377 from a mobile phone. Anonymous information can also be submitted to Crime Stoppers at 1-800-222-8477 or online at www.tipsubmit.com/start.htm.