No charges have been filed against the man and woman, who both appeared briefly in court Wednesday.
Federal prosecutor Lyne Decarie would not comment on the evidence against El Mahdi Jamali and Sabrine Djaermane.
But Decarie described their arrests Tuesday as a preventive measure that is justified "when police have reasonable grounds to fear that a person will commit a terrorist act."
Decarie told reporters she intends to seek peace bonds which will set out conditions the two must agree to.
Marc Giroux, Jamali's lawyer, said outside the courtroom it was the first time he has had to deal with such a case and that the country's police forces have become more sensitive in recent months.
"What's going on in the world, and especially what went on in Ottawa and Saint-Jean-sur-Richelieu, the police officers are kind of sensitive to that reality and I think it's kind of normal," he said.
"I don't say it justified the procedure but, that being said, the behaviour of the police is representative of the society in which we are living."
Last year, two soldiers were killed in separate attacks by so-called lone-wolf terrorists. Cpl. Nathan Cirillo died when he was shot while standing guard near Parliament Hill in Ottawa and Warrant Officer Patrice Vincent died after he was run over in Saint-Jean-sur-Richelieu, Que.
Giroux said his client was a bit bowled over that he was taken into custody and now has to deal with conditions he is not used to.
The lawyer also said family members who were in court were not happy that Jamali was being detained.
"It's never a nice experience to see that your child is being detained whatever the nature of the accusation is," Giroux said.
"They seemed surprised."
The two, who will be back in court on Monday, are the latest to be picked up by the RCMP under similar circumstances.
Two other Montrealers agreed in recent weeks to sign peace bonds amid terrorism-related fears.