Thirty-year-old man was deemed not to be a security threat because he wasn't actively recruiting, or showing a tendency toward violence

EDMONTON – A police national security team say they interviewed a young man in Edmonton about his extremist ideological musings two years before he was arrested for terrorism charges following knife and vehicle attacks in the Alberta capital.

In what police and politicians are calling a “lone-wolf” attack, which may have links to Islamic extremism, a city police constable directing traffic around a football game Saturday evening was struck by a car, then stabbed repeatedly in the head and face. An ISIS flag was found in the weaponized Chevy Malibu. Hours later, the same suspect was in a U-Haul truck, leading police on a lengthy chase and hitting four downtown pedestrians before his truck flipped and he was arrested.

The man was being questioned Sunday afternoon and had not yet been charged, though Edmonton police Chief Rod Knecht said the man is arrested on two terrorism offences, five counts of attempted murder and other offences.

Police confirmed the suspect is a Somali national who was a refugee. Multiple media reports identified him as Abdulahi Hasan Sharif.

WATCH: Edmonton police chief gives details of attack

In 2015, Edmonton police received a complaint that the individual was “espousing extremist ideology,” said RCMP Assistant Commissioner Marlin Degrand. After what Degrand described as “exhaustive investigation,” police deemed him not to be a security threat and lacked evidence to pursue terrorism charges or a peace bond.

“The suspect showed no signs of active recruitment or radicalization to violence at that time,” Degrand told reporters. “We had no intelligence that warranted keeping the suspect under investigation any further.”

Although the assistant commissioner confirmed that officers with a national security unit interviewed the suspect—“among others” at the time—he said there was no evidence anybody else was associated with the man’s extremist behaviour, or that he was part of any radical network.

Police, along with politicians at every level, urged strongly against pinning blame or casting aspersions on any group of people. The Alberta Muslim Public Affairs Council is organizing a vigil in downtown Edmonton, with Alberta Premier Rachel Notley and Mayor Don Iveson scheduled to attend.

The attacks began around 8:15 p.m. local time on Saturday, when the white Chevy Malibu slammed into Const. Mike Chernyk, a prison transport officer doing extra-time duty directing traffic around the Edmonton Eskimos football game at nearby Commonwealth Stadium. The collision, which happened about 45 minutes after the game started, sent Chernyk into the air, and video footage shows the driver getting out after the collision and stabbing the constable. While the knife sliced his head and face, Chernyk kept one hand protecting his firearm and the other fending off his attacker. He was able to fend off the man and chased him away.

Knecht said the constable has been released from hospital and is home recovering from injuries, expecting to make a full recovery.

The police chief’s remarks echoed reassurances earlier in the day from Iveson, the mayor, who described the attacks as the work of a lone wolf.

“It is vital now that we not succumb to hatred, that we not be intimidated by violence and that we respond with the loving strength of this whole community,” Iveson added. “We will not be divided. Terrorism is about creating panic and about sowing divide and about disrupting people’s lives. We can succumb to that or we can rise above it.”

Prime Minister Justin Trudeau condemned the violent events overnight ­as a “terrorist attack” and a “senseless act of violence.”

“Early reports indicate that this is another example of the hate that we must remain ever vigilant against,” Trudeau said in a statement, lauding first responders and police officers. “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.”

We'll never let violent extremism win. Canadians stand with the injured in Edmonton: https://t.co/4jZLhhbbla — Justin Trudeau (@JustinTrudeau) October 1, 2017

The extent of injuries to the four people injured by the van was not immediately known.

The attack on Chernyk occurred during a military appreciation night at the stadium. Canada’s chief of defence staff, Gen. Jonathan Vance, conducted the pregame coin flip and two CF-18 fighter jets did a fly-past before kickoff. More than 800 Boy Scouts were expected at the game and many were planning to camp out on the field afterward.

While the Eskimos were battling the Winnipeg Blue Bombers inside the stadium, the Malibu approached a traffic control post outside at a high speed.

Edmonton police released grainy footage of a car ramming a crowd control barricade with Chernyk standing beside it. The footage shows the officer being tossed about five metres into the air as the car slams into the front of a parked police cruiser.

The video also shows two people walking by with their dogs rushing towards Chernyk on the ground but they run off when the driver gets out of the car, runs over and appears to starts stabbing the officer.

Chernyk appears to wrestle with the driver on the ground and, at one point, it appears he is on top of the driver. Footage shows them both getting to their feet and the driver runs across the street while the officer slowly follows behind him into traffic.

Having seized the Islamic State flag from the front seat of the car, Knecht said, police launched a manhunt for the suspect, setting up checkstops around the area. They stopped a U-Haul truck at one a couple kilometres east of the stadium, and the driver’s identification matched the suspect’s.

But the cargo truck driver sped away, prompting a frantic chase that led down the Alberta capital’s main downtown drag, Jasper Avenue. The vehicle swerved toward pedestrians in crosswalks, then down an alleyway where smokers congregated outside a pub. Police managed to eventually prompt the truck to flip, one block south of Jasper Avenue and nearly 50 away from where it evaded the checkstop. Police used a stun grenade and immobilized the suspect with a Taser gun before arresting him, Knecht said.

At an earlier briefing, Knecht said there had been no warning for the attack.

Alberta Premier Rachel Notley called the events horrific.

WATCH: Notley comments on Edmonton attack

“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,” she said in a statement Sunday, praising first responders for their work.

“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.”

In a tweet Sunday, Public Safety Minister Ralph Goodale said “Canada will not be intimidated by terrorist violence.”

“At this time, the national terrorism threat level for Canada remains at ‘medium’ where it has stood since the fall of 2014,” his spokesman Scott Bardsley wrote, adding Canadians should report any suspicious activity.

Austin Elgie, manager of The Pint bar just west of the downtown core, saw the van zoom by with police giving chase. The van “peeled” into an alley where people were smoking, he said.

“There were like 10 cop cars following him … It was crazy. It just came around the corner, ripping. I thought at first he was pulling over for the cops coming by, but he was clearly the one they were chasing.”

Elgie said the van hit a man who was a bar customer.

“I have a registered nurse on my bar team and I grabbed her and had her look after the guy until the ambulance came. He was breathing and we got him in the ambulance and he was still breathing.”

The chase came to an end outside the Matrix Hotel, only a few blocks from the bar, when the van rolled on its side.

Natalie Pon tweeted that she was at a wedding at the hotel when the crash happened.

“They’re keeping us away from windrows/the lobby,” she said.

— with files from The Canadian Press