[Cronos]

A vigourous Zorastrian sect, the Qarmatians, attacked Arabia itself,

Dude -- I've lived in Bahrain for quite a few years -- the Qarmatians were Ismailis not Zoroastrians.

[BlackVeil]

I agree that they show some characteristics of the Ismailis, (and also of "twelver" shia Islam) but they are understood by many historians to have been following Zorastrian doctrines at that time. They violently separated from the Fatamid dynasty, and the Shah who banned Shariah and reinstituted the sacred flames in Bahrain would seem to be acting as a Zorastrian.