UPDATE: Iran radio says 457 people arrested, as nation's clerics battle to contain crisis.
Iranian authorities arrested at least 457 people after violent post-election clashes that left 10 people dead, state radio reported, as the nation's clerical leaders battled to contain the worst crisis since the Islamic revolution.
Opposition leader Mirhossein Mousavi, who has led a wave of massive protests over what he says was a rigged presidential election, remained defiant as he urged supporters to continue demonstrating but to adopt "self-restraint."
Iranian state radio, quoting the police, said the mass arrests were made when demonstrators and security forces clashed on Saturday around the capital's Azadi square in violence that left 10 people dead.
The streets of Tehran were tense on Monday but have remained largely quiet since Sunday and there were no immediate reports of any planned demonstrations. Witnesses said they did not see many security personnel out on the streets.
Mousavi, a post-revolution prime minister who lost to Mahmoud Ahmadinejad by a landslide according to official results from the June 12 election, told his supporters to continue their protests.
"The revolution is your legacy. To protest against lies and fraud is your right. Be hopeful that you will get your right and do not allow others who want to provoke your anger... to prevail," he said on his newspaper website Kalemeh.
But he urged his supporters -- who have adopted his green campaign colour -- to refrain from violence and show self-restraint. "The nation belongs to you," he said in a statement.
The foreign media has been barred from covering the demonstrations as part of tight new restrictions on their work since the upheaval began.
A total of 17 people have been killed and many more wounded, according to state media, while hundreds of protestors as well as prominent reformists, journalist and analysts have been rounded up in the post-election turmoil.
World leaders have voiced mounting alarm over the unrest, which has jolted the pillars of the Islamic regime and raised concerns over the future of the Shiite Muslim powerhouse, the fourth largest oil producer in the world.
Iranian leaders have lashed out at "meddling" by Western nations, and taken the foreign media and the exiled opposition to task.
The Guardians Council, the electoral watchdog has said it was ready to conduct a random recount of 10 percent of votes.