There is a difference between discrimination and being compltely and intentionally blind to race, religion, nationality, gender, age or whatever. The fact is, different cultures/religions/nationalities have their own customs, and its not at all discriminatory that they insist on hiring people who fit into the same group. When you see a woman in a burqa, you assume she's Muslim. When you see a man wearing the Russian hat thingy (I forget what its called), you can rightly assume that he is from the territory of the former Soviet Union or somewhere is Eastern Europe. Thats not discrimination, thats common sense.
To give you an example: it would be perfectly acceptable that a Baptist church hire only Baptists, because that is the central issue in the organization's identity. However, it would not be OK if they hired only Baptist males, if females we equally capable of performing the job. See the difference?