A couple from British Columbia who styled themselves as the sole members of "al-Qaida Canada" built pressure-cooker bombs and planted them on the grounds of the provincial legislature hours before Canada Day festivities, a prosecutor said Monday.

John Nuttall and Amanda Korody have pleaded not guilty to charges of conspiring to commit murder, conspiring to place explosives on behalf of a terrorist group, facilitating terrorist activity and possessing explosives on behalf of a terrorist group.

The pair was arrested in July 2013 after an undercover operation that began months earlier, when a Royal Canadian Mounted Police officer met Nuttall at a gas station near the man's home near Vancouver.

The bombs did not explode because undercover RCMP officers had ensured they were inert. But Nuttall and Korody intended to kill and maim an untold number of victims on the morning of July 1, 2013, prosecutor Peter Eccles told the jury at the start of the trial.

Nuttall, who wore a dark suit jacket, smiled during the hearing and occasionally turned to look at his mother in the public gallery. Korody wore a green shawl and mostly looked down as the prosecution outlined the allegations.

The undercover officer who met with Nuttall posed as an Arabic businessman who was searching for his niece and he enlisted Nuttall's help, Eccles said.

Nuttall told the officer that he was a recent convert to Islam and that he considered himself part of the mujahedeen, or holy warriors. Nuttall expressed his support for the Boston Marathon bombers, and he was particularly interested in the type of bomb they used/

The plan to target the legislature took shape over the next several months, Eccles said. Many of Nuttall and Korody's interactions with the undercover officers and each other were captured on video.

In late June, as the couple worked to assemble three bombs in a hotel room in Delta, south of Vancouver, the pair were captured on video in a private conversation, said Eccles.

"We are going to be listening to the news and see the aftermath," Nuttall was quoted as telling Korody. "This is going to rock the world. The whole world is going to hear about this — you know that, right? ... Al-Qaida Canada, that's who we are."

The undercover scenario involved the couple meeting another man, also a police officer, whose role was to provide C4 plastic explosives.

The second officer required Nuttall and Korody to each convince him they were serious about carrying out the attack, after which the couple donned masks and made a video outlining their plan, said Eccles.

In her taped segment, Eccles said Korody addressed her "brothers and sisters of the mujahedeen," telling them: "If you have a stone, throw it; if you have a bomb, drop it."

After the meeting, they gave the modified pressure cookers to their original undercover contact, who brought the bombs to an RCMP facility to be filled with harmless putty and a small amount of C4, said Eccles. The bombs could not have exploded, he said.

On Canada Day, Eccles said, the couple placed bombs in two planters on the legislature lawn. They were timed to explode 15 minutes apart, Eccles said.