"Twin brothers" from Ottowa, Canada, have been arrested and charged with terrorism offences.
Ashton Carleton Larmond and Carlos Larmond were charged with multiple counts related to terrorist activities, the Royal Canadian Mounted Police said in a statement.
They are both 24-years-old, and appear to be twins as they share the same birthday.
Carlos Larmond was arrested at Montréal-Pierre Elliott Trudeau International Airport on Friday, and is charged with "participation in the activity of a terrorist group, and attempting to leave Canada to participate in terrorist activity abroad".
Ashton Larmond was arrested in Ottawa, and is "charged with facilitating terrorist activity, participation in the activity of a terrorist group, and instructing to carry out activity for a terrorist group".
"Today's arrests speak to our ability to tackle a threat that is multifaceted and constantly evolving," said Canadian police official James Malizia.
"Through collaborative efforts with our partners, we were able to prevent these individuals from leaving Canada to engage in terrorist activity overseas," he said.
The arrests come after a terror attack in Canada's Parliament Hill in October, when Michael Zehaf-Bibeau shot dead a soldier at the Canada National War Memorial, before being killed trying to storm Canada's parliament building, while MPs were in session.
Two days previously, Martin Couture-Rouleau, who was allegedly inspired by Islamic State (Isis), ran over two soldiers with his car in Quebec, killing one. He was shot dead after a car chase with police.
Canada is part of the international coalition that has launched airstrikes against Islamic State targets in Iraq.
On Thursday, Canadian Prime Minister Stephen Harper announced that Canada was at "war" with Islamic State.
"This is a movement that has declared war on Canada specifically and has shown it has the ability to develop the capacity to execute attacks on this soil," he said at an event in Delta, British Columbia.