The protests come after the Iranian government admitted its armed forces "unintentionally" shot down a Ukrainian commercial plane, killing all 176 people on board.
"They are lying that our enemy is America, our enemy is right here", said protesters outside a university in Tehran in another clip cited by Reuters. As a result of the confession, hundreds of Iranians took to the street in protest on Saturday, demanding that Iran's Supreme Leader Ayatollah Ali Khamenei step down.
Meanwhile, at Isfahan University of Technology in the central Iranian city of Isfahan, protesters declared that the IRGC "commits crimes" and Iran's supreme leader "supports" them.
Another moderate daily Jomhuri-ye Eslami, or Islamic Republic, wrote in an editorial: "Those who delayed publishing the reason behind the plane crash and damaged people's trust in the establishment should be dismissed or should resign".
A senior Trump administration official, who declined to be identified, said the tragedy showed Iran's "reckless actions have again had devastating consequences". He did not offer his resignation.
Ukraine International Airlines flight PS752 bound for Kyiv, Ukraine, crashed minutes after take-off from the Imam Khomeini International Airport in Tehran on Wednesday just hours following the missile attack U.S. forces in Iraq in retaliation for the USA assassination of top Iranian commander Qassem Soleimani.
But others said Iran's enemies, a term usually used to refer to Washington and its allies, were exploiting the incident. Their alma maters were the site of protests Saturday evening.
A video circulated on social media shows that the government forces firing live bullet rounds on unarmed protesters at Azadi Square in Tehran.
After Iran made a huge admission on Saturday, the Canadian Prime Minister, Justin Trudeau renewed his call for answers from the Islamic nation.
The protests have garnered worldwide scrutiny amid fears of a crackdown by security forces. About 1,500 people were killed in less than two weeks of unrest, three interior ministry officials told Reuters, though global rights groups put the figure much lower and Iran rejected the figure. "Thousands have already been killed or imprisoned by you, and the World is watching", tweeted Trump. "More importantly, the US is watching".
UK Foreign Secretary Dominic Raab said "the arrest of our ambassador in Tehran without grounds or explanation is a flagrant violation of global law". Some lawmakers said the envoy should leave Iran before being ejected, media reported. He added in a tweet that he had left after five minutes when chanting broke out. He also demanded consular access for Canadian officials to work with grieving families of Canadian victims in Iran. Later that day, pro-government demonstrators burned United Kingdom and US flags.
The Pentagon chief says Iran's paramilitary Quds Force still presents a threat across the Mideast, but the specific attacks he says were being planned by Soleimani had been "disrupted".
Public fury at Iran's authorities had grown as questions about the plane crash mounted.