There were signs that the protesters’ enthusiasm was tapering off. Police dragged off a young man in a green shirt, the official color of the Mousavi campaign, without raising the hackles from pedestrians that erupted during similar encounters in previous days.

Judiciary official Ebrahim Raisi said special tribunals will be set up to process hundreds of “rioters” and “thugs” caught in security sweeps during the unrest after preliminary investigation.

“The judiciary will set up special courts for those cases which are passed on to the judiciary,” he said in comments broadcast on state television. “Hopefully, they will receive their legal punishments and our dear people will be informed of their punishments.”

The Tehran prosecutor’s office said it had arrested at least 457 people in Saturday’s unrest but a source inside Evin prison said nearly 1,000 had been brought in.