Iranian President Mahmoud Ahmadinejad condemned Israel and the US in a rally marking the annual Quds, or Jerusalem Day. Security was tight and coincided with reports that the house of opposition leader Mahdi Karroubi was under siege by pro-government militia members.
Iranian government TV showed crowds of demonstrators chanting "Death to America" and "Death to Israel" for the celebration of Jerusalem Day, an annual event to express support for Palestinians and to decry the existence of Israel.
Preparations for this year's event began well in advance, with government leaders urging a large turnout. Last year, opposition protesters overwhelmed parts of the demonstration, chanting slogans against the Iranian government and condemning repression of the popular Green Movement.
Government leaders were shown attending the event, surrounded by dozens of supporters. President Mahmoud Ahmadinejad, who has been locked in a struggle recently with adversaries inside the government, claimed that Jerusalem Day had strong popular support:
He says 75 million Iranians turned out for Jerusalem Day, today, and that hundreds of millions of others turned out to mark the event across the world. He adds that billions of people would turn out to mark Jerusalem Day if it were not for what he called the pressures of arrogant world powers and their threats of arrest and suppression.
Government TV used video taken by helicopter to try to show that there was a large turnout for the demonstration. Opposition supporters countered the claims with their own videos which appear to show a sparse turnout and a heavy security presence.
Friday, security forces deployed across Tehran, in an apparent bid to keep opposition demonstrators off the streets. Dozens of pro-government Basij militiamen on motorcycles surrounded the house of opposition leader Mehdi Karroubi, according to his news site Sahamnews.
Karroubi's home has been under siege for several days, with reports of violence and vandalism in the area. Karroubi's website also reported that Molotov cocktails were thrown at his building and that his top bodyguard had been badly beaten.
Iranian-born analyst Alex Vatanka of the Middle East Institute in Washington insists that pro-government forces have been mounting an ongoing campaign to de-legitimize the opposition Green Movement, as well as its top leaders:
"We've seen in the last few days how they've tried to keep Mehdi Karroubi away, trying to say Mr. Karroubi, Mr. Khatami, Mr. Mousavi, you are not part of whatever it is that you used to be part of," said Alex Vatanka. "Now, you are going to the dark side. You're not with the repressed Palestinians and you're not with the repressed Iranians."
Jerusalem Day began in the early 1980s after a call by Islamic Republic founder Ayatollah Ruhollah Khomeini to demonstrate against Israeli occupation of Jerusalem.
Alex Vatanka notes that this year's rally carries added significance for the Iranian government, because it was eclipsed in recent months by Turkey's spearheading of the failed aid flotilla to Gaza. "Iran," he argues, "wants to put itself at the forefront as defender of the most cherished Islamic cause it can find, which is Palestine."