Canadian authorities say they have arrested and charged two men with an al Qaeda-linked plot to "carry out a terrorist attack" against a passenger train thanks to the help of the Muslim community.
The Royal Canadian Mounted Police on Monday named the two accused as Chiheb Esseghaier, 30, and Raed Jaser, 35, from the Montreal and Toronto areas respectively.
Muhammad Robert Heft, who runs an outreach organisation for Islamic converts, and Hussein Hamdani, a lawyer and longtime advocate in the Muslim community, said one of the suspects was Tunisian and the other was from the United Arab Emirates.
Superintendent Doug Best said authorities were tipped off by members of the community of one of the suspects.
"It was sort of a thank you moment," Hamdani said.
"This tip, this lead, came from the Muslim community. But for the Muslim community we would not be talking about an arrest today.
"This is evidence and proof that the Canadian Muslim community, rather than a community that should be seen as suspect, is in fact partners for peace and here is the proof of it."
No Boston links
"The RCMP is alleging that Chiheb Esseghaier and Raed Jaser were conspiring to carry out an al-Qaeda-supported attack against a VIA passenger train," RCMP official James Malizia said.
"While the RCMP believed that these individuals had the capacity and intent to carry out these criminal acts, there was no imminent threat to the general public, rail employees, train passengers or infrastructure," the police said in a statement.
The police told a news conference that the suspects "were receiving support from al-Qaeda elements located in Iran" but added "there's no indication that these attacks were state-sponsored".
The pair, who are not Canadian citizens, were expected to appear in court in Toronto on Tuesday for a bail hearing.
Charges include conspiring to carry out an attack and conspiring in association with a terrorist group to murder individuals.
Officials in Washington and Toronto said there were no connections to last week's bombings at the marathon in Boston.
Canadian police and intelligence agencies said the operation to foil the plot was conducted in co-ordination with the US Department of Homeland Security and the Federal Bureau of Investigation (FBI).
We reject strongly and categorically any connection to this story.
Iran denies involvement in the plot after the arrests raised questions about the country's relationship with al-Qaeda.
"No shred of evidence regarding those who've been arrested and stand accused has been provided," Foreign Ministry spokesman Ramin Mehmanparast said, according to the Mehr news agency.
"In recent years, Canada's radical government has put in practice a project to harass Iran and it is clear that it has pursued these hostile actions."
Last September Canada severed diplomatic ties with Iran over its nuclear programme, its hostility towards Israel and what Ottawa said was Iran's support for terrorist groups.
Last autumn, the US administration offered up to $12m in rewards for information leading to the capture of two al-Qaeda leaders based in Iran.
The State Department described them as being instrumental in sending fighters to Iraq and Afghanistan.
Alireza Miryousefi, spokesman for the Iranian mission to the United Nations, said the group was not operating in Iran.
"Iran's position against this group is very clear and well known. [Al-Qaeda] has no possibility to do any activity inside Iran or conduct any operation abroad from Iran's territory,'' Miryousefi said in a statement emailed to the Associated Press late on Monday. "We reject strongly and categorically any connection to this story."
A spokeswoman for the Institut National de la Recherche Scientifique near Montreal confirmed that Esseghaier was a doctoral student at the research institute and that he had been arrested.
Julie Martineau, the school's director of communications, said Esseghaier arrived at the school in 2010 and was about midway through his degree.
"He is doing a PhD in the field of energy and materials sciences," she told Reuters.
In 2006, Canadian authorities arrested at least 18 suspects reportedly linked to a terror plot, involving attacks on the parliament and a major broadcast company.