The students say they were banned from classes after they protested the closing of a student publication by university officials.
The students say they were beaten by security forces and removed from their sit-in at the university on Sunday.
Protester Mahdieh Golrou told RFE/RL's Radio Farda that many students support the protest. Golrou -- who has not been allowed to attend classes for two years -- says she and the others will continue protesting until they have written permission that they can return to the university.
In the past three years, dozens of students have been banned from classes and suspended from studies because of their activism or criticism of the government.