That would be Christians and Jews especially...according to Jonah Goldberg.
The Western press suggested al Qaeda was simply confused and thought Americans lived in that foreign worker compound. That always struck me is as unlikely considering how good Qaeda intelligence must be inside Saudi Arabia.
It turns out the attacks killed mostly Lebanese Christians. Marshall makes the case that the press often obscures these distinctions behind phrases like "Arabs and Muslims were killed" which includes Christian Arabs.
For example that suicide attack at Maxim's in Israel did kill Arabs, but Catholic Arabs. The point is that al Qaeda has declared war against "infidels" which includes all Christians, Jews and many secular Muslims.