A video grab shows students trying to avoid stepping onto US flag lying on the ground.
For a second day protesters filled the streets of Iran.
The protesters pilled pressure on the government after the military admitted to shooting down a Ukrainian airliner mistakenly.
This happened at a time when Iran fears air strikes from the United States of America.
In Shahid Beheshti University in Tehran, students declined to run over the American flag.
Those that went ahead to step on the flag were made fun of and taunted.
“They are lying that our enemy is America, our enemy is right here," a group of protesters outside a university in Tehran chanted, according to video clips posted on Twitter.
Other social media posts showed demonstrators outside another university and another group of protesters in a different place marching to Tehran’s Azadi (Freedom) Square.
Aside from Tehran, protesters were seen marching in other Iranian cities.
The Ukrainian airliner was shot down early on Wednesday, a few hours after after Iran launched a ballistic missile attack on two military bases housing US troops in Iraq in retaliation for the killing of Iranian General Qassem Soleimani in an American airstrike in Baghdad.
A military statement carried by state media said the plane was mistaken for a "hostile target” after it turned toward a "sensitive military centre” of the Revolutionary Guard. The military was at its "highest level of readiness," it said, amid the heightened tensions with the United States.
All 176 aboard the plane were killed.
Move comes after a traumatic month in which the country had appeared on the brink of war with the United States and accidentally downed a Ukrainian passenger jet.
Bereaved friends and families joined in mourning after a Ukrainian airliner crashed near Tehran killing all 176 on board, as heartbreaking details started emerging about the victims, most of them from Iran and Canada.
The report by Iran's civil aviation organisation cited witnesses on the ground and in a passing aircraft flying at high altitude as saying the jet was on fire while still aloft.
Sheikh Mohammed Bin Zayed expressed his thanks to Sheikh Tamim Bin Hamad for his congratulations and the sincere fraternal feelings he showed, wishing the brotherly State of Qatar and its people further progress and development.
Sheikh Sultan’s statement reads, “The Ruler of Sharjah congratulates Mansour Bin Zayed Al Nahyan on his appointment as Vice President."
Sheikh Mohammed said, “I congratulate my brothers Sheikh Hazaa, Sheikh Tahnoun, Sheikh Mansour and Sheikh Khaled Bin Mohamed for the confidence in the President of the State. In you and your brothers, the leaders of the new generation, the march continues.”