MELISSA BLOCK, host:
In Tehran today, hardliners in the Iranian Parliament pumped their fists in the air and called for opposition leaders to be executed.
Unidentified Group: (Chanting in foreign language)
BLOCK: This, one day after anti-government protesters filled streets of the capital chanting death to the dictator. They were the largest demonstrations since the government cracked down on the opposition movement 14 months ago.
Washington Post correspondent Thomas Erdbrink joins me from Tehran.
And, Thomas, why don't you describe yesterday's protests - the size and the scope of them?
Mr. THOMAS ERDBRINK (Correspondent, The Washington Post): Well, it's hard for me to judge as foreign journalists are barred from reporting directly from the protests, but what I understand from witnesses is that there were more people there than expected. The estimates range between tens of thousands and hundreds of thousands.
Those people gathered along Tehran's central boulevard, the Enghelab Revolution Street, where they tried to basically pass a route from an eastern square all the way to a square in the western part of town. And all along that route, there were many, many people and many skirmishes also with security forces.
BLOCK: And from what you've been able to tell, how did the government respond? How much of a crackdown was there?
Mr. ERDBRINK: Well, it was actually quite surprising. This demonstration had been announced a week ago by the opposition political leaders: Mr. Mir Hossein Mousavi and Mehdi Karroubi, the former presidential challengers.
But on the day of the demonstration, I heard that there were not too many security forces present, at least not compared to previous demonstrations in 2009. And this apparently gave the protesters the opportunity to gather quickly and therefore made it hard for the riot police, which did show up about half an hour to 45 minutes later, to disperse the people. Well, teargas was shot. Some people were beaten with batons.
And as the sun started setting, the members of the paramilitary Basij force also showed up. Now, these are volunteers that as a goal tried to protect Iran's Islamic system and things turned more violent.
What witnesses told me was that people attacked members of the Basij, and today, authorities said that at least one of those Basijs has died.
BLOCK: The opposition leaders, whom you mentioned, Thomas, Mousavi and Karroubi, they've been put under house arrest. Is that correct?
Mr. ERDBRINK: Yes, they've been under house arrest, and I think what we're seeing now here is a sort of watershed moment. They have been tolerated by Iran's leaders in the last year. There was a kind of unspoken (unintelligible) in which the opposition leaders will not call for protests and in which they would also not be arrested in return.
What is happening now is that after Monday's protests, Iran's supreme leader, Ayatollah Ali Khamenei, who has publicly said that he wants to give the opposition leaders a chance to return in the warm embrace of the system and now has to make a decision whether these opposition leaders will be arrested, which might spark new protests, or whether they can remain under a sort of house arrest, which might make Iran's leaders not give a very clear signal to their supporters. So that's a very tough decision that's upcoming now.
BLOCK: Thomas, you saw these big demonstrations in Tehran yesterday. It sounds like a pretty quiet day there today. Is there a sense in Tehran that these protests will build, that you'll see waves of demonstrations, as you saw back in 2009?
Mr. ERDBRINK: No. I actually don't expect to see a wave of protests. Now, we mustn't forget it could be - if, for instance, the opposition leaders are arrested in the coming week, that that will lead to new protests, but for now, no new dates have been planned.
BLOCK: Thomas Erdbrink is a Washington Post correspondent in Tehran.
Thomas, thanks very much.
Mr. ERDBRINK: Thank you.