The demonstration is the third student protest in a week, the first sizeable student unrest in the Islamic Republic under the hard-line leader, who came to power in 2005 and began reversing earlier reforms.
A group of students began chanting anti-presidential slogans and smashed Iranian state television cameras installed to cover the event at Amir Kabir University. Other students, however, shouted out support for Ahmadinejad, Fars said.
Hundreds of students joined a rally at Amir Kabir University of Technology, a leading Iranian research institute, Sunday to protest against a clampdown on members of the reformist Muslim Student Association.
An earlier student rally in the Islamic Republic's capital Wednesday was held to draw attention to government tyranny.
Tehran is reportedly hosting a conference to establish whether or not the Holocaust ever took place, and if so to verify its true scale.
Ahmadinejad has said the Holocaust is a myth and that Israel should be "wiped off the map." He has also defied international demands that Tehran stop its uranium enrichment, raising fears in the U.S. and other countries that Iran is seeking nuclear weapons.
