Complex sentence: Muslims belong to the Shi'a and Sunni branches of Islam, with Shi'a constituting over 70% of the Muslim population but are treated as "second-class citizens" by the ruling Sunni monarchy.
Split into simpler sentences: Muslims belong to the Shi'a and Sunni branches of Islam. The Shi'a constitute over 70% of the Muslim population but are treated as "second-class citizens" by the ruling Sunni monarchy.