Students at different universities across Iran held sit-ins on Saturday amid increasing pressure on activists on campuses after almost three months of unrest.

The protesters at universities demanded the release of imprisoned students, lifting of harassment against others and slammed the execution of the 23-year-old protester Mohsen Shekari.

In Tehran’s Beheshti University they held a protest rally in silence amid the strong presence of plainclothes regime agents and security forces.

Reports from Allameh University in Tehran say over 100 students have been banned from entering the campus after they called for a protest over the suspicious death of their colleague, Shahabuddin Hashemi.

The hanged body of Shahabuddin Hashemi was found in the dormitory of Allameh University on Thursday, but state media claimed he committed suicide as a result of his mental problems.

However, his brother, Mehdi Hashemi denied the claims on social media as “dirty lies”, saying his brother's “suspicious murder” is reported as a “fake suicide by legal authorities.”

In western city of Sanandaj, security forces attacked protesting students at a technical college while the female students were setting fire to the Islamic Republic’s flag.

Security forces have repeatedly raided campuses and faced off with student protesters. Over 140 universities have been the scene of anti-regime protests nationwide and nearly 600 students have been detained as of Thursday, according to the US-based Human Rights Activists News Agency (HRANA).