Iran's pro-reform leader Mir Hossein Mousavi addressed tens of thousands of supporters in the Iranian capital Tehran Mondduring a huge rally to protest the re-election of President Mahmoud Ahmadinejad. There were reports by eyewitnesses that a demonstrator was killed by gunfire from a building used by a pro-government militia.
Iranian protesters say they will hold another protest Tuesday in defiance of government warnings and in spite of the shooting death of a demonstrator Monday at a massive pro-opposition rally in Tehran.
The protest defied a government ban on demonstrations, but security forces watched quietly.
Mousavi addressed the cheering crowd, waving green flags and banners and shouting slogans against the government.
He says our people are seeking respect and and seeking to defend their votes and their rights.
Mr. Ahmadinejad has faced demonstrations and riots since Saturday, after officials announced his landslide victory. (See slideshow of eyewitness accounts of Tehran protests)
Many in the crowd chanted slogans to decry President Ahmedinejad.
One Mousavi supporter at Monday's rally complained that the election was 'stolen' and the vote was rigged. "We are here just to say 'No' to Ahmadinejad. We already -- all of us -- we said 'Yes' to Mir Hossein Mousavi Friday night. And because of corruption, they corrupted our election," the supporter said.
But an Associated Press photographer reported as the rally was ending he saw one person shot and killed and several others who appeared to be seriously wounded in Enghelab Square. Eyewitnesses say the gunfire came from a compound for the Basij religious militia, which is linked to Iran's powerful Revolutionary Guard
The country's supreme leader Ayatollah Ali Khamenei has ordered an examination into Mousavi's claims of vote rigging.
Despite restrictions placed on journalists and the blocking of internet web sites and cell phone text messaging in Iran, thousands of Mousavi supporters continue to find ways post hundreds of messages to a support group on the Facebook website.
Dozens of pictures of police brutality were posted, including a young man drenched in blood, and a black-clad riot policeman pounding demonstrators who had fallen to the ground."
"This is the start of a brand new revolution," wrote one young man who identified himself as Reza on the Mousavi Web site. "It is not going to stop."
Despite what appears to be the growing momentum of popular discontent, Tel Aviv-based Iran analyst Meir Javedanfar of the MEEPAS center says close scrutiny is needed to determine where the situation in Iran is heading.
"I think it depends on three factors: Number one, how senior are the people who are going to become involved in the demonstrating; the more senior they are, the more people will become encouraged. Number two; if the demonstrations spread to other cities. I think the more cities that become involved, the more the leadership will take notice. And, also, number three; the duration of this. If this continues for another two weeks, I think the Supreme Leader [Ayatollah Ali Khamenei] will have a serious situation on his hands. Until then, we should sit down and watch the developments and see what the Supreme Leader says," Javedanfar said.
The U.S. State Department has issued a statement saying it is "deeply troubled by reports of violence, arrests and possible voting irregularities."