After last week's deadly bombing in Boston, news that Toronto foiled its own terrorist attack might have come as a relief.

A plot to blow up a rail line between Canada and the U.S. was thwarted on Monday, and Canadian police have arrested two suspects, Chiheb Esseghaier, of Montreal, and Raed Jaser, of Toronto.

But the most surprising part of the story might be how the suspects were discovered: They were turned in, reports say, by leaders of their own community.

Muhammed Robert Heft, who runs Toronto's Paradise Forever Islamic Center, says that one of the suspects -- he won't say which -- started expressing extremist beliefs to a member of the city's Muslim leadership a year ago.

"They were espousing some views that were starting to ruffle feathers and make people uncomfortable," Heft said. "They focused on demonizing Western society and suggesting that there has to be some kind of retribution or revenge for the perceived grievances of this individual."

The community leader -- Heft declined to give his name -- became concerned, and suggested to Heft that he monitor the suspect.

"It went to a stage where it was a constant topic of conversation. The community leader realized that the person was not changing their views. They worried that something might eventually happen," he explained.