TORONTO -- Canadians face a far more serious threat from lone-wolf terrorists than from large terrorist groups such as al-Qaida or the Islamic State, a disaster management conference heard Tuesday.

Speaking at one of the sessions, Andrew Majoran, general manager of the Mackenzie Institute, said detecting and foiling large-scale plots tends to be easier for the intelligence community than picking up on the radicalized, violent individual secretly plotting mayhem.

"A lot of the time when a lone-wolf attack occurs, nobody had any idea it was coming," Majoran said in an interview before his talk.

"It's so difficult to gather intelligence on them. You're talking about a lone wolf who keeps to himself."

A classic example of what Majoran calls the "pure" lone wolf is Anders Breivik, a Norwegian who went on a horrific killing rampage in Oslo in 2011. While Breivik kept a journal and had a manifesto, no one else had access to his plans.

In Canada, Michael Zehaf-Bibeau, who gunned down a soldier in Ottawa before storming Parliament Hill last October, and Martin Couture-Rouleau, who deliberately ran down a soldier in Saint-Jean-sur-Richelieu, Que., were domestic examples of lone wolves -- although they had been on the radar of intelligence authorities but had not done enough to warrant arrest.

Lone wolves, however, aren't necessarily completely solitary individuals, Majoran said. Some, like Oklahoma City bomber Timothy McVeigh, might act with one or two others who share the same murderous sense of purpose.

One up-and-coming threat that is easily overlooked is the female lone wolf, he said. Examples include Islamist student Roshonara Choudhry, who stabbed a British MP in a 2010 assassination attempt, and "Colleen (Jihad Jane) LaRose, an American who tried to set up an Islamic extremist cell.

Majoran said community vigilance -- citizens spotting and reporting something abnormal -- is one of the best approaches to mitigating the lone-wolf threat.

Community complacency, however, might be the biggest obstacle -- because their backgrounds are so mundane and familiar, Majoran said. These are people who went to schools and universities with us, have jobs and families.

"Lone wolves can slip through the cracks quite easily," Majoran said.

The World Conference and Disaster Management in downtown Toronto also heard from experts on dealing with disasters ranging from fire and floods to disease outbreaks, power failures and infrastructure collapses -- each bringing its own challenges.

Some attendees, who came from 38 countries, took part in an exercise involving a mock passenger plane crash in downtown Toronto.

About a dozen people cloistered themselves behind computer screens in an "emergency operations centre" set up in a convention centre room. There, they watched incoming data on casualties and other aspects of the crash as they tried to come up with an effective response in terms of helping the injured, preventing further casualties and ensuring public awareness.

"Our role is to support the command centres on the ground and to co-ordinate the overall community response," exercise leader Lyle Quan told the group.