Iranians have gathered in the streets of Tehran to demand the resignation of Ayatollah Seyed Ali Khamenei after the regime admitted it had mistakenly shot down a civilian passenger plane.

Angry crowds gathered on Saturday night in at least four locations in Tehran, chanting 'death to liars' and calling for the country's supreme leader to step down over the tragic military blunder, video from the scene shows.

What began as mournful vigils for Iranian lives lost on the flight soon turned to outrage and protest against the regime, and riot police quickly cracked down, firing tear gas into the crowd. 

'Death to the Islamic Republic' protesters chanted, as the regime's security forces allegedly used ambulances to sneak heavily armed paramilitary police into the middle of crowds to disperse the demonstration.

Ukrainian Airlines Flight 752 was carrying 176 people, at least 130 of them Iranian citizens, when it was shot down by hapless Iranian Revolutionary Guard air defense forces shortly after taking off from Tehran on January 8.