John Stewart Nuttall and Amanda Marie Korody -- who were detained Monday, Canada Day -- allegedly planned to use pressure cooker devices on the building in Victoria, the Royal Canadian Mounted Police said.
Police said that while Nuttall, 38, and Korody, whose age was given as either 28 or 29, were "inspired by Al-Qaeda ideology," they appeared to be acting alone.
"There is no evidence to indicate that these individuals had the support or were acting at the direction of a terrorist group, per se," police said.
There was no evidence linking the two arrested individuals to those behind the Boston Marathon bombing in April, who also used pressure cooker devices, or the two people arrested in Toronto the same month for a plot to bomb a passenger train, police said.