Analysis of information sources in references of the Wikipedia article "Iranian Call and Reform Organization" in English language version.
In Iran, there is a big Islamic organization called "Islah and Dawa Group" that belongs to the Muslim Brotherhood. They are not registered as a political group because political activities are not allowed in Iran. Obviously, the regime in Iran is a sectarian regime and will always try to limit the activities of local Sunnis. Islah and Dawa are not happy with the regime's sectarian policies, but I think there is very little they can do if they want to stay away from serious trouble. Because of their Muslim Brotherhood ties, they have good relations with the KIU.