A mail bomb headed to the United States that was intercepted in England last month had a high risk of exploding over Canada, according to flight data.
Information from Houston-based company Flightaware indicates that UPS Flight 232 from England to Philadelphia was 257 kilometres northwest of Quebec City at 5:30 a.m., the time British police say the bomb was set to go off.
The bomb was removed from the Oct. 29 flight at England's East Midlands airport.
British police said earlier Wednesday the bomb could have detonated over the United States. However, flight data indicates the plane did not enter U.S. airspace until about 6 a.m.
While Flight 232 operates daily, it follows one of two routes. If the Oct. 29 flight had taken its other route, it likely would have been over U.S. airspace when the bomb was timed to detonate.
A spokesperson for Public Safety Minister Vic Toews told The Canadian Press that Canada remains on alert for any potential national security threats.
"It is clear that Canada is not immune from international or home-grown radicalization," Christopher McCluskey said in an email.
"Our law enforcement and security agencies work closely together with their international counterparts, and we are always looking for new ways to co-operate with other countries to strengthen our mutual safety and security."
The bomb was one of two sent from Yemen to addresses in the United States last month. The second was intercepted in Dubai.
The bombs were hidden in toner cartridges for computer printers and wired to cellphones, which had their communication cards removed, according to U.S. officials, making it likely the phones' alarms were timed to detonate the bombs.
The bombs contained syringes containing lead azide, a chemical initiator that could have set off the explosive PETN found in the cartridges. Both chemicals were used in the attempted bombing of a U.S. airliner last Christmas.
As a result, the Canadian government announced earlier this week new security measures that ban large, office-sized printer cartridges from some flights.
According to the new measures, passengers flying from a Canadian airport into the United States are not permitted to travel with ink and toner cartridges that weigh 454 grams or more in their checked or their carry-on luggage.
Passengers flying from a Canadian airport to a domestic destination or an international destination outside of the U.S. cannot carry the large cartridges in their checked luggage either. These passengers may carry the cartridges as carry-on -- however, Transport Canada warns cartridges belonging to these passengers will be taken out and subject to further screening.
Officials have blamed the most recent incidents, as well as the failed Christmas bombing, on al Qaeda's affiliate in Yemen, which has become increasingly active under radical U.S.-born cleric Anwar al-Awlaki.
With files from The Associated Press
