The protest began in front of Tehran University as a small group of women began chanting freedom, freedom and calling for a referendum on religious rule.
The rally grew rapidly as thousands of local inhabitants and passers-by joined the protesters.
Hundreds of uniformed and plain-clothed security agents quickly circled the protestors to prevent thousands more joining their ranks. Agents of the notorious secret police, the Ministry of Intelligence and Security (MOIS) and the paramilitary Bassij forces were ferried to the streets around Tehran University to disperse the demonstrators.
Cries of Freedom, equality, down with dictatorship could be heard at the scene, as protestors tore down campaign posters of all election contenders and urged passers-by to boycott the polls.
Protesters were able to break through police ranks in Enghelab Street and move towards Enghelab Square and then Karegar Avenue. Thousands had joined the throngs of protesters as they made their way towards Keshavarz Boulevard, destroying all election posters and placards on their way.
In a reference to gender inequality in the theocratic state, protesters chanted, Unequal law, inhuman justice, human rights can only exist in a free Iran, and Misogyny is the root of tyranny.
Security agents and paramilitary policemen were seen hitting women with batons. In some cases, angry women protesters retaliated and beat some of the security agents before being dragged to security forces vans and driven away.
By nightfall, sporadic clashes were still being reported in several streets near the main route of the protest.