The investigation that culminated in the arrest of 17 terrorism suspects had its start in 2004, authorities say, when tech-savvy spies noticed a group of youth espousing anti-Western rhetoric in an online chat room.

Fall 2004: Canadian Security Intelligence Service agents noticed some teens reading and posting to radical Islamist websites, espousing anti-Western views, sources revealed to the Toronto Star.

November 2004: The Royal Canadian Mounted Police was brought into the case by CSSIS agents who believed they had enough information to launch a criminal investigation.

Three tonnes of what was believed to be ammonium nitrate, but was in fact a harmless substances, was purchased from undercover officers.

March 2005: Two Americans who popped onto the radar of authorities after communicating by email with the Canadian group hopped onto a bus for two round-trip tickets to Toronto.

According to U.S. court documents, they were to meet with "like-minded Islamists."

"According to Ahmed ... they met regularly with at least three subjects of an FBI international terrorism investigation," the court documents allege, and discussed "strategic locations in the United States suitable for a terrorist strike."

August 2005: Canadian investigators were watching closely as a car tried to cross back into Canada across the Peace Bridge in Fort Erie.

The Star says the car was allegedly rented by Fahim Ahmad, 21 -- who is one of the suspects facing terrorism charges.

When the car was stopped at the border, another two suspects -- Yasin Abdi Mohamed, 24, and Ali Dirie, 22 -- were found inside.

Mohamed was carrying a loaded handgun while Dirie had two pistols found on his body.

Both of the men, who are landed immigrants, told the court they had the guns for their own protection.

They pleaded guilty and both are now serving two-year sentences.

Winter 2005/2006: Police allege some of the younger members allegedly went north to what is being described as a "training camp."

February 2006: Intelligence analysts called a briefing for chiefs of Ontario's police forces to bring them into the loop of what they believed was a high-level terrorist threat

June 2, 2006: SWAT teams raided several residential homes in Toronto and nearby Mississauga and arrested 12 men and five youths on terrorism charges.