41 arrested in connection to twin attacks claimed by ISIS.
Some of these groups are ethnic or religious based and have opposed the regime for decades.
Iranian authorities have criticized a rising alliance between Washington and Riyadh against Tehran.
The aim of the military exercise in Semnan province was to "showcase the power of Iran's revolution and to dismiss the sanctions."
Government controlled media in Iran did not comment or acknowledge the arrests but Arab media outlets have been covering the story quite extensively.
It was at least the fourth such incident in less than a month. US officials are concerned that these actions by Iran could lead to mistakes.
General Qasemi, a crony of Iran's supreme leader, urged the annexation of Bahrain to Iran, explaining that "Bahrain is an Iranian province that was detached from Iran due to the colonialism."
Rezaian, Tehran bureau chief for the Washington Post, was detained on July 22, 2014 and imprisoned for nine months without charges.
"They created the myth of nuclear weapons so they could say the Islamic Republic is a source of threat. No, the source of threat is America itself."