Canadian police have arrested a third man in an alleged terrorist conspiracy.

Royal Canadian Mounted Police said Monday that 21-year-old Suliman Mohamed has been charged with participating in the activity of a terrorist group.

On Friday, twin brothers linked to Mohamed, Ashton Carleton Larmond and Carlos Larmond, were charged with terrorism-related offences. Carlos Larmond was arrested Friday at Montreal's airport on charges of intending to travel overseas for terrorist purposes. A government official familiar with the matter said they were trying to get to Syria. The official spoke on condition of anonymity because they weren't authorized to speak publicly.

Police declined to provide details.

A lawyer for the brothers said they plan to vigorously dispute the charges.

RCMP Chief Supt. Jennifer Strachan said the recent arrests underscore the reality that there are individuals in Canada who have become radicalized to a violent ideology.