Iranian state television has reportedly claimed that the students were not aware of Ahmadinejad's speech at the university and that their protest had nothing to do with the visit.
The YouTube videos, however, suggest that the students were angry about Ahmadinejad's presence:
In this video, students chant, "Students die, but they don't accept humiliation and abjectness."
Here, students chant, "Today is a day of mourning. Ahmadinejad, the liar, is our guest today."
This video apparently shows security forces in front of the university.
The protest comes a day after five people, including a teacher, were executed at the Evin prison.
The executions have stirred outrage among rights activists and intellectuals.
On May 1, a group of students at Tehran University also protested against the Iranian president, who was attending a ceremony there.
-- Golnaz Esfandiari