Alan Bell, a former member of the British special forces who now runs a consulting firm in Toronto, said Canadians are largely in denial about the possibility of an attack that could come in the form of a radioactive dirty bomb or suicide attack.

For example, Bell said airport security has improved in some areas in the years following the 9-11 terrorist attacks, but suffered in others.

"We get searched every time we get on - they take our aerosols, our razors, old ladies' knitting needles - but all the food and freight that goes on the same aircraft isn't searched at all," Bell told delegates at the annual Canadian risk management conference in Halifax.

"So, it makes a mockery of the whole thing."

Bell said that while businesses are the targets of the majority of terrorist attacks around the world, companies in Canada are still doing little to prepare for or detect a threat.

He urged businesses to assess risks they might face, develop response plans to attacks and rehearse them, and safely store potentially dangerous products like fertilizers, which can be used to make bombs.

Bell, who spent 12 years in Britain's Special Air Service, suggested so-called dirty bombs can be obtained easily in Canada and placed on buses, subways or in large malls or apartment complexes.

He cited the arrest of 17 men in Toronto last year after they were found to have obtained three times the amount of ammonium nitrate fertilizer used in the 1995 Oklahoma City bombing, which killed 168 people.

At the time, police said the arrest foiled a series of terrorist attacks aimed at unspecified targets in southern Ontario.

"The question is: Are we ready for suicide bombings? The answer is no. Are we prepared for a 9-11 type of situation? The answer to that question is no, we are definitely not."