This article indicates at least one perpetrator is Muslim, in his own words.
http://www.freerepublic.com/focus/f-news/1208111/posts
I did not claim that the perpetrators were not Muslim. Apparently this is the majority religion in Chechnya. I questioned whether the hostage takers were Arabs as stated by the authorities, but denied by the survivor accounts I have read. I would believe the survivors over government spokemen who may have various agendas that cause them to lie.