I would say that it's more refugee boys, because they have often lived through several years of trauma, torture, and being helpless. Many of them are from single-parent households, usually with a mom. So due to their background, the only way they know how to deal with conflict and lack of success—and they find this in school—is through violence.
We also have quite a bit of gang violence in Ottawa, and a lot of this is perpetrated by refugee boys.