Canadian authorities have thwarted plot to carry out a major terrorist attack

Canadian police and intelligence agencies will announce later today they have thwarted a plot to carry out a major terrorist attack, arresting two suspects in Montreal and Toronto, CBC News has learned.

Highly placed sources tell CBC News the alleged plotters have been under surveillance for more than a year in Quebec and southern Ontario.

The two men are expected to appear in court tomorrow.
Police have made a number of arrests in southern Ontario and Quebec following a joint operation between Canadian and U.S. authorities. (CBC)
The investigation was part of a cross-border operation involving Canadian law enforcement agencies, the FBI and the U.S. Department of Homeland Security.

Law enforcement officials say the terror suspects arrested today have no connection to the two brothers accused of last week's Boston Marathon bombings.  More