Tehran is saying farewell to assassinated leader Ayattolah Ali Khamanei.
Huge crowds, with some mourners chanting and others weeping, are lining the 10km (6.2 miles) route for the late leader's coffin.
The cortege will pass through the landmark Engelab - or Revolution Square. It is dominated by a towering statue in the form of a massive clenched fist known as the fist of defiance, the defining symbol of these ceremonies with its slogan: "We must rise."
Another refrain is rising too among the regime's most loyal defenders - revenge for the supreme leader's assassination by US and Israeli air strikes.
Red flags symbolising vengeance now colour the crowds, and posters single out US President Donald Trump.
The BBC's Chief International correspondent, Lyse Doucet, reporting from the Iranian capital, says some of it is just slogans, but fury over the Ayatollah's killing also fuels anger within the ranks of Iran's new leaders, with the most hardline condemning the negotiations with Trump’s team.
source: commonspace.eu with BBC (London) and agencies