TORONTO (REUTERS) - A group of "murderous misfits" planned to massacre as many people as possible in a Valentine's Day shooting spree that police foiled after an anonymous tip-off, Canada's justice minister said on Saturday.
Police arrested three people, including an American woman, before the attack in the eastern city of Halifax could take place.
A fourth man linked to the plot was found dead in a house in Halifax, police said.
"Based on what we know so far, it would have been devastating, mass casualties would have been a real possibility," Justice Minister Peter MacKay told reporters.
"The attack does not appear to have been culturally motivated, therefore not linked to terrorism."
MacKay said a 19-year-old Canadian man and a 23-year-old American woman, believed to have been in contact online, allegedly planned to open fire at an unidentified public venue.
"This appeared to be a group of murderous misfits that were coming here, or living here, and were planning to wreak havoc and mayhem on our community," MacKay said.
"To be clear, all suspects are either dead or in custody."
Extra security measures have been taken at the public venue, he said.
Police said on Friday they obtained information that suggested the two had access to firearms and intended to kill people, and then themselves.
Nova Scotia RCMP commanding officer Brian Brennan told CBC News on Friday that the alleged attackers were "a group of individuals that had some beliefs and were willing to carry out violent acts against citizens".
Evidence suggested two other Nova Scotia males, aged 20 and 17, were involved, though their roles had not yet been determined, police said.
Police said they found the 19-year-old male dead at a residence early on Friday and the 20-year-old male and 23-year-old female were arrested at Halifax airport.
The 17-year-old male was arrested elsewhere.