Yes, religion was the enabler of this unfortunate story. And many horrible things have happened either in the name of religion, or as a consiquence of religious beliefs.
However, we must be careful not to fall into the trap of believing religion only causes evil. This is the same tactic used against Atheists in pointing out the horrors that Stalin employed, or against those who support the ToE by pointing to the atrocities employed by those who used Social Darwinism as an excuse to commit genocide, or allowing the socially unfit to die out.
Mankind will sometimes use any excuse, be it religion, nationalism, philosophy, or any obscure rational to excuse their own ignorance and heartlessness.