Two Surrey residents accused of planting pressure cooker bombs outside the B.C. legislature on Canada Day are described by police as "Al-Qaeda-inspired" but "self-radicalized."

B.C. RCMP arrested John Stewart Nuttall and Amanda Marie Korody in Abbotsford at 2 p.m. Monday afternoon after a five-month investigation that began in February.

The alleged homegrown terror plot is similar to that of the Boston Marathon bombers, who used pressure cooker bombs to send shrapnel through the crowd near the race's finish line on April 15.

RCMP seized what they are calling three "improvised explosive devices" that were made from pressure cookers that contained nails, bolts, nuts and washers and were placed on the legislative assembly grounds.

Nuttall, 38 and Korody, 29, are charged with making or possessing an explosive device, conspiracy to commit an indictable offence, and knowingly facilitating terrorist activity.

"These individuals were inspired by Al-Qaeda ideology," RCMP Assistant Commissioner James Malizia said. "Our investigation has determined this was a domestic threat without international linkages."

The alleged motive of the two accused is not clear.

Police wouldn't discuss any connection to or religion, but landlords in north Surrey as devout Muslim converts whose unstable behaviour was alarming enough to prompt calls to police.

The RCMP says the pair "took steps to build explosive devices and place them at the British Columbia Legislature in Victoria where crowds were expected to gather on Canada Day."

The legislative lawn and inner harbour were crowded with an estimated 40,000 revelers for Monday's Canada Day concert and fireworks.

Police aren't saying if undercover officers were working with the duo but Malizia said they were being closely monitored and police ensured the bombs were inert and could not detonate.

"While the RCMP believed this threat was real, at no time was the security of the public at risk," Malizia said. "We detected the threat early and disrupted it."

The arrests were made after of the RCMP E Division, the Canadian Border Services Agency and the Canadian Security Intelligence Service, dubbed Project Souvenir.

"I want to reassure our citizens that at all times during the investigation, our primary focus was the safety and protection of the public," Malizia said.

Nor was the Canada Day crowd in Victoria the only potential target that may have been contemplated.

"The suspects were committed to acts of violence and discussed a wide variety of targets and techniques," said RCMP Assistant Commissioner Wayne Rideout, adding they were "self-radicalized" and aimed to cause "maximum impact to Canadian citizens at the B.C. Legislature on a national holiday."

A variety of covert investigation methods were used to control any method the suspects had to commit harm, he added.

Rideout said the bombs are believed to have been made in Surrey and at other locations in B.C.

"As these devices were constructed we were in very tight control," he said. "We were confident that public risk was absolutely minimized."

Surrey Mayor Dianne Watts said the two alleged terrorists have lived in Surrey for about 18 months and had a transient lifestyle, moving fluidly in the region from Delta to Surrey to Vancouver.

She couldn't say whether the pair had substance abuse issues.

"I can't confirm that, I know that they had significant challenges in their life," Watts said.

She also understands they gathered much of their information about what they were doing from the internet.

"I think they're fairly unsophisticated," Watts said.

Korody has no prior criminal charges, but Nuttall was convicted of robbery in 2003 in Victoria and received an 18-month conditional sentence. An addicted drug user at the time, Nuttall had hit a businessman on the head with a rock and stole his briefcase.

In March 2010, he was convicted of assault, mischief and possessing a weapon for a dangerous purpose B´ÎÔª¹ÙÍøÍøÖ·“ also in Victoria B´ÎÔª¹ÙÍøÍøÖ·“ and received a 60-day conditional sentence (house arrest) and one year of probation.

B´ÎÔª¹ÙÍøÍøÖ· sources have identified as Nuttall's, where he has posted four of his own songs, two of them titled "In League With Satan" and "The End of the World".

Nuttall and Korody appeared in Surrey Provincial Court Tuesday and make their next appearance July 9.

Victoria was the site of at least one terrorist plot in the past, the Millennium bomber plot in 2000. Ahmed Ressam, an Algerian member of Al Qaeda, assembled bomb materials while staying at a Vancouver motel, then loaded them in the trunk of his car and traveled to Victoria.

Ressam attempted to enter the U.S. on the MV Coho ferry from Victoria to Washington, but he was arrested by U.S. border security at Port Angeles.

B´ÎÔª¹ÙÍøÍøÖ·“ with files from Tom Fletcher, Kolby Solinsky, Kevin Diakiw and Vikki Hopes

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