RCMP say they have arrested two people who were allegedly plotting to attack a Via Rail passenger train.
The suspects were arrested in Toronto and Montreal.
Police named them as Chiheb Esseghaier and Raed Jaser. The investigation was part of a cross-border operation involving Canadian law enforcement agencies, the FBI and the U.S. Department of Homeland Security.
The alleged plotters have reportedly been under surveillance for more than a year.
The arrests are not connected to the Boston Marathon bombings.