TEHRAN, Iran (CNN) -- Shouts of "Allahu Akbar," or "God is great," a sign of continuing protest in Iran, could be heard Tuesday night in north and west Tehran, along with shouts of "death to dictator."
In addition, pictures and videos were posted online of a reported protest at the University of Kashan, south of the capital city.
The shouts were heard and reports came a day after the Islamic republic warned reformists against taking to the streets in protest, as the 30th anniversary of the Iranian hostage crisis approaches.
Iran -- still reeling from the massive demonstration that followed the country's disputed presidential election -- on Wednesday will commemorate November 4, 1979, when a group of Islamist students seized the U.S. Embassy in Tehran, taking 53 hostages and effectively ending diplomatic relations with the United States. Dozens of Americans were held against their will for 444 days.
While the government will allow the "faithful" to celebrate the anniversary of the hostage crisis, those who "intend to gather illegally and spread lies among people who gather to peacefully participate ... will be held responsible for their actions," said Ahmad Reza Radan, head of Iran's security forces, according to the semi-official Iran Student Correspondent Association.
In the University of Kashan videos, the students are singing a revolution song from 1979. The song is about students being arrested and jailed during the Islamic Revolution in that year.
The government of Iran arrested more than 1,000 people in a massive crackdown after the June 12 election, in which the incumbent, President Mahmoud Ahmadinejad, was declared the overwhelming winner.
In the aftermath of the fallout, the government accused several reformists, including opposition candidates Mehdi Karrubi and Mir Hossein Moussavi, of spreading anti-government propaganda and fueling the anger among the public.
Despite warnings from Iran's hard-line leaders, the reformists have largely refused to back down. They released the names of 72 protesters they say were killed in the unrest that followed the election -- more than double the government's official number.
Karrubi, a former parliamentary speaker, has been especially vocal about the claims of detainee rape -- even publishing a first-hand account of one alleged victim recently on his Web site. He has been scorned by government hard-liners, whose credibility and legitimacy have been publicly questioned since the elections.
Islamic authorities tried to preemptively silence anti-government demonstrations and rhetoric.
According to the Islamic Republic News Agency, Hossein Sajedinia, deputy of operations for Iran's security forces, said, "The police will not allow a handful [of individuals] to disrupt the organization and safety of this day, by fooling people and the youth."
CNN's Shirzad Bozorgmehr, Sara Mazloumsaki and Octavia Nasr contributed to this report.