Hadi Heydari, Fatemeh Arabsorkhi, Mohammad Shafeai and Alireza Taheri have been detained.
According to the RAHANA reporter, the police forces raided the house of Fatemeh Arabsorkhi, a reformist figure, last month and took her computer, picture, notes and personal belongings. They presented her with a summons order on that day.
The detain activists been transferred to the Evin Prison but the reason for the arrests has not been disclosed.
The family members of Mohammad Nourizad and Fakhrosadat Mohtashamipour were also arrested several days ago near Evin Prison and released after a few hours.