Answer:
Shias, Sunni
Step-by-step explanation:
Shia and sunni are two of the main sects of Islam. While Middle east is region with demography mainly of consisting of Islam nature, there are two major country who are consistently in conflict with each other, Iran and Saudi Arabia. Shia and sect are also in conflict with each other owing to gain of power in middle east. Hence the two countries are divided based on these two sects.
while Shias make about 95% of Islam majority in Iran, shias make around 80% of total population Saudi Arabia.