The Royal Canadian Mounted Police have charged and arrested another Ottawa man with terror-related offences.

21-year-old Suliman Mohamed was arrested in Ottawa following a national security criminal investigation. He is charged with conspiracy to participate in the activities of a terrorist group.

Mohamed's father spoke to reporters outside of court, and said he heard about the charges in the media. "I know my son" said Idris Altahir, "he doesn't participate in these things but we'll see what evidence they have. He's my son, he's a Muslim like I am but he's not a terrorist."

Mohamed is also facing a charge in connection to the arrests of identical twin brothers Ashton and Carlos Larmond . He has been charged with conspiracy to participate in a terrorist activity with the Larmond twins.

Police allege the three men hatched a plan to join a terrorist organization, while living in Ottawa's Vanier neighbourhood.

They were known at a local mosque but not well.

Carlos Larmond, 24, was arrested by the RCMP on Friday at Montreal's international airport. Police say he was trying to board a plane. He was subsequently charged with attempting to leave Canada to participate in terrorist activity abroad, and with participating in the activity of a terrorist group.

Ashton Carleton Larmond, also 24, was arrested in Ottawa on Friday. He has been charged with facilitating terrorist activity, participation in the activity of a terrorist group and instructing to carry out activity for a terrorist group.