On Tuesday Canada expelled the Syrian diplomats stationed in this country. It was a response to the Houla massacre in Syria, where more than 100 people were killed, including dozens of women and children.
Blame for that massacre has fallen on the shoulders of a powerful militia known as the Shabiha.
Martin Chulov is the Middle East correspondent for The Guardian. He tells us who the Shabiha are and the violent role they are playing in the conflict.