Police in Ottawa took a fourth man into custody Friday as public speculation about an alleged terror cell turned to discussion of possible targets.
However, the fourth man detained was not charged with any offences, and many of the terrorist motivations remained mysterious, two days after police teams swooped to arrest three young Muslim men on allegations they were plotting terrorist acts.
Sources say the key allegation remains that the men were in possession of sophisticated long-range remote bomb detonators - a technological leap forward, sources say, over the thwarted plans of terrorists who previously targeted Canada.
Fifty-odd circuit-boards were seized by police this week and once again these detonation devices will be central in a Canadian terrorism case.
The latest circuitry discovered is disturbing. Sources say it could have set off many explosions from a triggerman several hundred metres away. While the devices were assembled in Canada, police say the were partly built out of know-how acquired from terrorists overseas.
Details of the plot remain fuzzy, but there is speculation that Parliament Hill was a target on a terrorist hit list. The alleged plot was disrupted at such an early stage, however, it would be difficult to suggest there were any hard-and-fast targets.
Hiva Alizadeh, an Iranian Canadian, is the only one of the accused facing charges of handling bomb components and financing terror. He has been on the radar screen of Canadian security agencies for years.
Police said they arrested Mr. Alizadeh and two accomplices this week to "prevent the suspects from providing financial support to terrorist counterparts" who could have potentially struck at NATO forces in Afghanistan.
A year's worth of round-the-clock investigation by an estimated 100 police officers in many cities led to the arrests. However, after all this investigation, authorities still seem to be in the dark on many key details.
Canadian authorities have scant ability to gather evidence or arrest suspects overseas - especially in places like Iran, Afghanistan and Pakistan. Three un-indicted co-conspirators are named in the Canadian criminal complaint and remain at large outside Canada.
Despite the long look at Mr. Alizadeh and his associates, police say they moved in at an earlier juncture than in past terrorism cases - when bomb plots were feared to be imminent.
In 2004, Mounties rammed down the doors of an Ottawa computer programmer's home and seized circuitry that could trigger an explosion from up to 300 metres away. Two years after that, a more rudimentary cell-phone-triggered detonator was seized from the home of Toronto gas-station attendant.
Both men - Momin Khawaja and Zakaria Amara - and their accomplices were eventually convicted of plotting terrorist bombs and sentenced to long penitentiary terms.