They are also mourning the dead, which included many young people who were studying overseas. The US leader backed the anti-government protests in the Islamic Republic and promised to "continue to stand" with the Iranian people.
Suffocating US sanctions have sent Iran into deep recession, and a rise in the official price of fuel in November led to the largest protests in the 40-year history of the regime, to which the government responded by cutting off internet for several days and killing hundreds of demonstrators.
They will also pay attention to how the victims of the air crash are treated by the Iranian elite.
Iran's military said its air-defense forces unintentionally shot down the Boeing 737-800 airliner on January 8, killing all 176 people on board.
Fars, which is close to conservatives, said the protesting students chanted "destructive" and "radical" slogans.
There was no immediate report in Iranian state-run media on the incident near Azadi, or Freedom, Square in Tehran on Sunday night after a call went up for protests there.
The videos, which were posted by the New York-based Center for Human Rights in Iran on Sunday, could not be immediately verified.
Ukrainian President Volodymyr Zelensky said the prosecutor general has opened an investigation into the "murder" of 11 Ukrainian citizens who were on board the doomed plane and that his government will provide financial assistance to their families while calling upon the global community to insist upon a full investigation into the crash.
"Our profound regrets, apologies and condolences to our people, to the families of all victims, and to other affected nations", Iranian Foreign Minister Mohammad Javad Zarif said on Twitter.
IRGC officials said the plane had been mistaken for a cruise missile.
"The government will pay UAH 200,000 of assistance to the families of those who were killed in the plane crash in Iran and will monitor the proper payoff of insurance payments in accordance with the Montreal Convention", the press service said.
Iran downed the flight as it braced for possible American retaliation after firing ballistic missiles at two bases in Iraq housing USA forces.
"We reach out to local lawmakers [in Maryland] and ordinary people to tell them Iran is not what they see on television", he said.
Protesters shouted demands for Iran's Supreme Leader Ayatollah Ali Khamenei to step down.
The Trump administration, on the other hand, far from learning any sobering lesson from the sordid episode that still threatens to spiral out of control, has instead sniffed an opportunity in the protests to further ratchet up pressure on the Iranian regime.
Demonstrations at home against Iran's rulers are the latest twist in one of the most destabilizing escalations between the United States and Iran since the Iranian revolution of 1979.
"There cannot be another massacre of peaceful protesters, nor an internet shutdown", he wrote.
Speaking at a memorial for victims in Edmonton Sunday, Trudeau said he's learned about who they were, what they loved doing and what their hopes were for the future.
"The Iranian government is at a crossroads moment", he said. "Azadi Square. Death to the dictator!" The wrong group, he said, was being punished: "It's as if civilians had brought down a military plane".
"One of the biggest points of contention has been this idea of wanting to support the Iranian protest movement against the Islamic regime in Iran while the same time not beating the drums of war", she told VOA in a phone interview.
Hola, 50, who knew one of the victims, could not hold back her tears.