JIM LEHRER: New violence erupted in the capital city of Iran today. An army of police and militia forces beat down the latest protest against the presidential election outcome.
We begin our lead story coverage with a report narrated by Jonathan Miller of Independent Television News.
JONATHAN MILLER: It was just across the street from parliament that it all kicked off this afternoon. At 5:40 local time, we started getting messages. The first, reports of clashes and tear gas; then, at 6 o'clock, that a young woman had been shot.
And, in quick succession, a flood of other messages that Basij paramilitaries had weighed in, beating people seen using mobile phones.
"They've cornered us in alleyways," one said. "It's like a mousetrap."
There were reports of fires, helicopters overhead, and then, on Twitter, a description of the square as "a war zone, blood everywhere."
IRANIAN WOMAN: They beat a woman so savagely that she was drenched in blood. And her husband, who was watching the scene, he just fainted. They were beating people like hell. This was a massacre. They were trying to beat people so that they would die.
JONATHAN MILLER: There is real difficulty corroborating these reports or to stand up when or where pictures like these were filmed, but they were posted on the Web within the past two hours.
In the anonymity of the Tehran night, they still shout, "Allahu Akbar," "God is great," a call of defiance that's echoed down through 30 years of revolution.
Large numbers of Iranians are losing faith in their Islamic revolution now and are putting their lives on the line, but its supreme leader, whose authority is under serious threat, has dug his heels in.
AYATOLLAH ALI KHAMENEI, Iran Supreme Leader (through translator): The entire nation should respect the law. I had insisted and will insist on implementing the law on the election issue and keeping the law of the country. Neither the establishment nor the nation will yield to pressure at any cost.
JONATHAN MILLER: Parliamentary deputies responded with "Allahu Akbar," too, then, "Khamenei is our leader," and an obligatory chant, "Death to America."
Human rights groups claim there have been more than 1,000 arrests across the country. Many detainees in Tehran have been taken to Evin Prison, where they're reportedly being held incommunicado with no access to lawyers and without charge.
The supreme leader said that, if this doesn't stop, the blood will be on the hands of opposition politicians disputing the result of the presidential election. One of them today, the former commander of the Revolutionary Guard, throwing in the towel.
TV PRESENTER: Presidential candidate Mohsen Rezaei has withdrawn his complaints...
JONATHAN MILLER: Others aren't so easily intimidated. Shia clerics have been openly involved in protests. And today, Iran's rebel Grand Ayatollah Montazeri declared on his Web site that, "Resisting the people's demand is religiously prohibited."
Nothing's been heard from the defeated presidential candidate Mir Hossein Mousavi for days now. Another candidate, though, Mehdi Karroubi, has called for a protest tomorrow to mourn the dead.