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Chris was up all night keeping tabs on this critical moment in Iran. Reports of an attack on Karoubi here, as the junta brought in masses of pro-government supporters to pre-empt the protests; state TV is using Fox News-style old footage of scene in Azadi square for Ahmadi's rally - without live sound;  the square itself was wired off in advance; there are confirmed reports that Karroubi's son was arrested, and that Khatami's brother and wife were temporarily detained; Ahmadinejad's speech is videoed and twittered here; the first videos coming out of the country are here, with a new chant: "Referendum! Referendum! This is the slogan of the people." Ahmadinejad's boast that the country his junta controls has broken past a key nuclear threshhold is exposed as almost certainly a lie here; a video of desultory pro-government chants by small groups of demonstrators can be seen here.

As the day progressed, larger rallies began to turn into clashes, in Mashad and Isfahan:

1005 GMT: North Tehran is the scene of “sporadic and at times heavy” clashes, especially at Vanak Square. That is notable, since Vanak had been relatively free of clashes in demonstrations in November and December, including Ashura.

1000 GMT: Farda News is reporting that former President Hashemi Rafsanjani participated in the rally today at Enghelab and Palestine Streets.

0940 GMT: The mainstream site Mardomak is calling the security forces on Tehran’s streets “akin to a military regime”.

There's an update on the Gmail crackdown here. The basij - some looking like Hezbollah thugs - arrive on the scene here, Widespread terror of the basij can be seen in gripping videos here. Scenes of crushing army and police forces preventing any rallies in central Tehran are here. Reports of shootings here. Any members of the foreign press were forced to listen to Ahmadinejad's rants, as reported here and prevented from covering any of the protests elsewhere. The sense begins to develop that this has been a major victory for the junta, as Tehran Bureau reports:

Everyone we have spoken to so far this morning has said about the same thing: "A big anticlimax," "defeat," "An overwhelming presence from the other side. People were terrified."

Eye-witness accounts of brutal attacks on the increasingly few protestors on the streets - assaulted with chains, cables, batons and gas - here. The junta seems to have been able to keep any big crowds from assembling by brute force, although the full picture is at this point unknowable. A physical assault on Moussavi's wife, Zahra Rahnavard, is reported by Robert Mackey here.

I want to thank Chris for his night-shift of extraordinary work. The three of us will keep as much information as we can find coming.

Please pray for the great and courageous people of Iran.

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