CAIRO (AP) -- Riot police attacked hundreds of demonstrators with tear gas and fired live bullets in the air to disperse a rally in central Tehran Monday, carrying out a threat by the country's most powerful security force to crush any further opposition protests over the disputed presidential election.
Britain, accused by Iran of fomenting post-election unrest, said it was evacuating the families of diplomats and other officials based in Iran - the first country to do so as Iran's worst internal conflict since the 1979 Islamic Revolution escalated.
Witnesses said helicopters hovered overhead as about 200 protesters gathered at Haft-e-Tir Square. But hundreds of anti-riot police quickly put an end to the demonstration and prevented any gathering, even small groups, at the scene.
At the subway station at Haft-e-Tir, the witnesses said police did not allow anyone to stand still, asking them to keep on walking and separating people who were walked together. The witnesses asked not to be identified for fear of government reprisals.
Just before the clashes, an Iranian woman who lives in Tehran said there was a heavy police and security presence in another square in central Tehran. She asked not to be identified because she was worried about government reprisals.
"There is a massive, massive, massive police presence," she told The Associated Press in Cairo by telephone. "Their presence was really intimidating."
Iran says at least 17 protesters have been killed in a week of unrest so far after the electoral council declared hard-line President Mahmoud Ahmadinejad winner of the June 12 election. His main challenger, Mir Hossein Mousavi, charged the election was a fraud and insists he is the true winner. His followers have been staging near-daily rallies, at least one of them drawing a massive crowds of hundreds of thousands.
Severe restrictions on reporters have made it almost impossible to independently verify any reports on demonstrations, clashes and casualties. Iran has ordered reporters for foreign news agencies to stay in their offices, barring them from any reporting on the streets.
The country's highest electoral authority, the Guardian Council, acknowledged on Monday that there were voting irregularities in 50 electoral districts, the most serious official admission so far of problems in the election. But the council insisted the problems do not affect the outcome of the vote.
Earlier Monday, the elite Revolutionary Guard issued its sternest warning so far in the post-election crisis. It warned protesters to "be prepared for a resolution and revolutionary confrontation with the Guards, Basij and other security forces and disciplinary forces" if they continue their near-daily rallies.
The Basij, a plainclothes militia under the command of the Revolutionary Guard, have been used to quell street protests that erupted after the election result was announced.
The Guard statement ordered demonstrators to "end the sabotage and rioting activities" and said their resistance is a "conspiracy" against Iran. On Sunday, acting joint chief of the armed forces Gen. Gholam Ali Rashid issued a thinly veiled warning to Mousavi, saying "we are determined to confront plots by enemies aimed at creating a rift in the nation.
Ali Nader, an Iran specialist for the RAND Corp. think tank, said the Guard's crackdown threat was no surprise.
"I don't think their willingness to crack down was ever in doubt. They won't let these protests grow - this was the way the shah was brought down" in 1979, Nader said, but added: "Even if the protests peter out, you can expect a strong opposition movement in Iran."
Mousavi vowed Sunday night to keep up the protests, in defiance of Supreme Leader Ayatollah Ali Khamenei, who holds ultimate power in Iran. In a sermon to tens of thousands on Friday, Khamenei said demonstrators must stop their street protests or face the consequences and he firmly backed Ahmadinejad's victory.
"The country belongs to you," Mousavi's latest statement said. "Protesting lies and fraud is your right."
Mousavi's Web site called Monday for supporters to turn on their car lights in the late afternoon as a sign of protest.
Mousavi's latest statements posted on his Web site also warned supporters of danger ahead, and said he would stand by the protesters "at all times." But he said he would "never allow anybody's life to be endangered because of my actions" and called for pursuing fraud claims through an independent board.
The former prime minister, a longtime loyalist of the Islamic government, also called the Basij and military "our brothers" and "protectors of our revolution and regime." He may be trying to constrain his followers' demands before they pose a mortal threat to Iran's system of limited democracy constrained by Shiite clerics, who have ultimate authority.
Mousavi ally and former president Mohammad Khatami said in a statement that "protest in a civil manner and avoiding disturbances in the definite right of the people and all must respect that."
Britain's Foreign Office said it was pulling staffers' dependents out because "the families of our staff have been unable to carry out their lives as usual."
In Washington, President Barack Obama said he does not want to become a scapegoat for Iran's leadership as the postelection upheaval continues, but Republicans continued criticizing him for being overly cautious.
The Czech EU presidency summoned the Iranian charge d'affaires to reject claims by Iran that the 27-nation bloc has been interfering in its internal affairs.
Iran state media reported at least 10 people were killed in the fiercest clashes yet on Saturday and 100 were injured.
A graphic video that appears to show a young woman dying within minutes after she was shot during Saturday's demonstrations has become the iconic image seen by millions around the world on video-sharing sites such as YouTube.
Police said Monday that 457 people were arrested on Saturday alone, but did not say how many have been arrested throughout the week of turmoil.
The country's highest electoral authority agreed last week to investigate some opposition complaints of problems in the voting. The Guardian Council said Monday it found irregularities in 50 voting districts, but that this has no effect on election outcome. Council spokesman Abbas Ali Kadkhodaei was quoted on the state TV Web site as saying that its probe showed more votes were cast in these constituencies than there were registered voters.
But this "has no effect on the result of the elections," he said.
Mousavi has demanded that the election result be annulled and a new vote held.
Khatami said "taking complaints to bodies that are required to protect people's rights, but are themselves subject to criticism, is not a solution" -- effectively accusing the Council of collusion in vote fraud.
The government has intensified a crackdown on independent media - expelling a BBC correspondent, suspending the Dubai-based network Al-Arabiya and detaining at least two local journalists for U.S. magazines.
English-language state television said an exile group known as the People's Mujahedeen had a hand in the street violence and broadcast what it said were confessions of British-controlled agents.
The exile group, also called the Mujahedeen-e-Khalq, is the military wing of the Paris-based National Council of Resistance of Iran. The council says it is dedicated to a democratic, secular government in Iran, but the military wing has been blacklisted by the United States and the European Union as a terrorist organization.
The Foreign Ministry lashed out at foreign media and Western governments, with ministry spokesman Hasan Qashqavi accusing them of "a racial mentality that Iranians belong to the Third World."
"Meddling by Western powers and international media is unacceptable," he said at a news conference shown on state TV, taking particular aim at French President Nicolas Sarkozy.
"How can a Western president, like the French president, ask for nullification of Iranian election results?" Qashqavi said. "I regret such comments."
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