Politicians and Muslim community leaders are cautioning against potential community backlash after a suspected terrorism attack in Edmonton Saturday night. 

A 30-year-old man is in custody following a high-speed chase just before midnight through streets filled with bar patrons and football fans. A man stabbed a police officer with a knife and deliberately plowed into pedestrians on Edmonton's busiest downtown strip, police say.

Abdulahi Hasan Sharif is the man accused in the attacks, multiple sources tell CBC News. 

The chase ended after a white U-Haul van the man was driving struck four pedestrians and flipped on its side. Cst. Mike Chernyk was the officer injured in the violent altercation, sources tell CBC News.

Edmonton police Chief Rod Knecht confirmed that a black ISIS flag was seized from a car where the police officer was attacked. The officer was not critically injured. The condition of the four pedestrians is not known.

"Based on evidence at the scenes and the actions of the suspect ... it was determined that these incidents are being investigated as acts of terrorism," Knecht said.

The incident triggered a torrent of hate messages on social media, much of it targeting Muslims.

'Hatred has no place in Alberta' 

Alberta Premier Rachel Notley thanked first responders for bravery during the chaotic night and urged the public to avoid lashing out. 

"The horrific events last night in downtown Edmonton have left us shocked and angry," Notley said in a statement. "It's left us shocked at the indiscriminate cruelty and angry that someone might target their hatred at places where we gather with our families and friends.

'Alberta we must stand together in defence of our loved ones, friends and neighbours'3:12

"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."

Edmonton Mayor Don Iveson called for vigilance and urged the community to remain calm.

 "To the best of our knowledge this was a lone wolf attack," Iveson told a news conference Sunday. "Terrorism is about creating panic and sowing divide and disputing people's lives, so we can succumb to that or we can rise above it."

Members of Edmonton's Muslim community are strongly condemning the attacks and calling for solidarity within the community.

Edmonton human rights activist Ahmed Abdikadir said he felt "anger and frustration" at news the violence may have been the work of a terrorist. He fears the attack may result in a backlash against the city's minority communities. 

"To the Edmonton community at large, I would like to tell them that we stand together and unite against hate. And let's solve this problem collectively, rather than pointing fingers at each other.

"Pointing at one community or the other will not be the solution."

Police believe the suspect acted alone, Knecht said early Sunday, adding that police are nonetheless investigating the possible involvement of others.

map

The first attack happened at about 8:15 p.m. Saturday near Commonwealth Stadium, where an officer was working traffic control for a CFL game.

Knecht said the officer was standing behind a barricade when a Chevrolet Malibu crashed into it, hit the officer and sent him flying 4.5 metres into the air.

"A male believed to be 30 years old then jumped out of his vehicle and viciously attacked the Edmonton Police Service member with a knife," Knecht said. "A struggle then ensued, during which the male suspect stabbed the officer several times before fleeing the scene on foot, northbound down 92nd Street."

The officer was taken to hospital, but his injuries are not critical.

WARNING GRAPHIC CONTENT: Police release video of suspect car ramming police officer1:06

At around 10 p.m., police told a news conference that a manhunt was underway, but there was no threat to the public.

Just before midnight, a white U-Haul van was pulled over at a checkstop on the north side of town. When a police officer checked the driver's name, he recognized it as being similar to the name of the registered owner of the car that had struck the officer at Commonwealth Stadium.

'The police cars just kept coming'

The U-Haul immediately sped off toward downtown Edmonton, where streets were filled with Saturday night bar crowds and football fans. 

As bystanders watched, the van barrelled down Jasper Avenue with up to 20 police vehicles following.

"The police cars just kept coming. They just kept coming," said Jaylene Ellard, who was out with a friend on the crisp fall evening.

Another witness said the vehicles were driving up to 80 km/h in the 50 km/h zone.

"That high-speed chase should have never, ever in a million years have happened downtown," said Brian McNeill, who was in a parking lot with a group of friends when the vehicles sped past.

One witness said police cars began to block streets that connect to Jasper Avenue. The U-Haul eventually doubled back and drove the opposite way down Jasper Avenue. Near 107th Street the van struck at least two pedestrians.

"Throughout the chase, the U-Haul truck deliberately attempted to hit pedestrians in crosswalks and alleys in two areas along Jasper Avenue," Knecht said. 

The van continued until it flipped and landed on its side.

Pat Hannigan was about a quarter-block away when he heard a loud bang.

"I saw the van on its side, it flipped over, U-Haul van," he said. "And they had a guy handcuffed on the ground and obviously they smashed out the window. They had a pipe or something in their hand."

Knecht said officers did not stop the chase along the busy downtown street "due to the seriousness of the offence — or the believed offence."

'We are urging Edmontonians to be vigilant'3:11

Video released by police

Police have since released surveillance footage of the suspect. The grainy video shows a car ramming into pedestrians, including a uniformed officer, at a police crowd control barricade near the stadium where the Edmonton Eskimos football game was being played.

The footage shows the officer being thrown about five metres into the air as the car slams into the front of a parked police cruiser.

Two people are shown walking toward the officer on the ground, but they run off when the driver gets out of the car and appears to start repeatedly stabbing the officer.

The police officer appears to wrestle with the driver on the ground. After a struggle, both the suspect and officer get to their feet before the driver runs across the street, with the injured officer following.

Reaction from Trudeau

Prime Minister Justin Trudeau issued a statement of support on Sunday.

"The Government of Canada and Canadians stand with the people of Edmonton after the terrorist attack on Saturday," he 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. 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.

"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."

During a news conference on Sunday, Public Safety Minister Ralph Goodale said the National Terrorism Threat Level for Canada "remains at 'medium,' where it has stood since the fall of 2014.

Goodale said  the suspect was on a "police watch list," but declined to provide further details on the investigation or the suspect's criminal background. 

Police are scheduled to hold another news conference at 3 p.m. Sunday.

Edmonton police are working with the RCMP's Integration National Security Enforcement Teams on the investigation.

With files from Andrea Ross and Zoe Todd