Thousands of riot police and members of the Basij militia lined the streets of Teheran on Sunday, and numerous helicopters clattered overhead, yet protesters continued to defy the regime by holding sporadic peaceful marches and gatherings denouncing the Iranian leadership and mourning the victims of Saturday's bloody crackdown. New amateur video footage showed hundreds, or possibly thousands of protesters on the march, shouting to one another "Don't be afraid" and repeating the now familiar call of "Death to the dictator." The Iranian authorities officially acknowledged 10 fatalities in Saturday's violent response to the protesters, whose initial demonstrations over the allegedly rigged June 12 presidential elections have now escalated into open defiance of the regime. But unofficial reports suggest the death toll is far higher. The state has also acknowledged seven more fatalities earlier last week. Watch the latest from youtube: "When my generation fought against the shah in 1979, we did not experience the same animal tactics that this regime uses on our young," one contact in Teheran told this reporter, underlining that the current turmoil represents the greatest threat to the Islamic regime since it seized power 30 years ago. "We have never before seen this kind of merciless killing out on the streets," he went on. "Undercover police walk by and stab an innocent man or women in the crowd, motorcycle attackers crush the bones of our people with their clubs, and more people are being shot down..." Dissident Ayatollah Hossein Ali Montazeri, who is currently under house arrest, issued a call for three days of mourning for the victims, and many Teheran businesses stayed closed on Sunday in what amounted to a partial strike. "The regime thinks we will go to work as though nothing happened? No way. Unless President Mousavi tells us otherwise, we will not work," said one source, deliberately describing the defeated challenger Mir Hossein Mousavi as head of state, rather than the purported election winner, incumbent Mahmoud Ahmadinejad. Britain's Chatham House think tank said it had seen partial results of the June 12 elections showing pro-Ahmadinejad voting patterns it called "highly implausible." In two provinces, it also said, the votes counted exceeded the number of potential voters. "We will remain strong and will fight back," said another contact. "People are switching numbers on their houses, so we can confuse the Basiji. And I heard something about putting nails and glass in the streets to slow down" their vehicles, said another source. Turning up its rhetoric against the figurehead of the new protests, and underlining how utterly the post-election chaos has split the regime, state media on Sunday denounced Mousavi as "a criminal." Mousavi said that the people are entitled to protest fraud and lies, in a statement released on Sunday on the Web site of his newspaper Kalameh, quoted in AFP. "I, as one of the mourners (of the Saturday killings), invite my dear people to self-restraint. The nation belongs to you," the presidential candidate said in the statement. "The revolution is your legacy. To protest against lies and fraud is your right. Be hopeful that you will get your right and do not allow others who want to provoke your anger... to prevail," Mousavi said.. Mousavi, also appealed to the protesters to "keep on refraining from violence." He also appealed to police and "not to act in such a way" which was causing "irreparable" damage to relations with normal people. Al-Arabiya TV reported that he had compared the regime's use of violence against demonstrators to the reviled practices used by the shah. He also reportedly denounced the shootings and arrests, accusing the government of breaching provision 27 of the Iranian constitution, which grants the right to protest peacefully. His supporters issued statements denying reports on Saturday that he had declared himself ready for "martyrdom." In a telephone interview from Teheran, this reporter was told that Mousavi's headquarters in the capital was destroyed by plainclothes police officers late last week and that increasing numbers of the "reformist" inner circle are now being arrested. Other reports said five members of former president Hashemi Rafsanjani's family were taken into custody. Rafsanjani's daughter, Faeza Hashemi, who is known to have addressed opposition protests, was the last to be released, after reportedly refusing to sign a commitment not to take part in further demonstrations. Another of Mousavi's prominent supporters, former president Mohammad Khatami, warned that the government's crackdown "will have dire consequences." Khatami said Ahmadinejad's assertions of foreign media meddling in Iran were insulting, and called for a nationwide investigation of vote fraud. Some of the worst violence on Saturday, sources told this reporter by telephone, took place on Teheran's Valiasr Street, where riot police on motorbikes violently broke up a gathering in front of a Basij building. Women protesters fought back with sticks, one source said, and the protesters later destroyed the building. Many Iranian civilians died in that confrontation, the source said. "I can't believe how brave our women are," said one contact. "I have seen some even remove their hijab during the rallies and fight off the police more bravely than the men." The security forces "opened fire on the crowds," said this source. "And the police would not let the injured into the hospitals unless they were Basij members. The source also said that civilians being treated in Teheran hospitals were "pulled off their beds and arrested." Meanwhile, CNN on Sunday night broadcast new footage from the minutes before the new symbol of the opposition protests, 27-year-old philosophy student Neda, was shot dead by a Basij militiaman in Teheran on Saturday. The new footage showed Neda and her grey-haired father walking among peaceful protesters, doing nothing to prompt the fatal fire. Moments later she was shot in the chest, by the Basij gunman on a rooftop, and the her father is seen desperately trying to keep her alive as the blood oozes from her body. Other footage reaching the West on Sunday included the harrowing sight and screams of a mother whose seven-year-old boy has been beaten by police. Police and members of the Basij militia took up positions Sunday afternoon on major streets and squares, including the site of Saturday's clashes. After dark, many people in Teheran went to their rooftops to shout "Death to the dictator" and Allahu akbar." Also Sunday, Parliament Speaker Ali Larijani said on state television that the number of people questioning the election results was large and "this group should be respected and one should not mix this big population's account with a small group of rioters." Rafsanjani, 75, heads two powerful institutions. One of them, the cleric-run Assembly of Experts, has the power to monitor and remove the supreme leader, the country's most powerful figure. The second is the Expediency Council, a body that arbitrates disputes between parliament and the unelected Guardian Council, which can block legislation. The assembly has never publicly reprimanded the unelected Supreme Leader Ayatollah Ali Khamenei since he succeeded Islamic Revolution founder Ayatollah Ruhollah Khomeini in 1989. But the current crisis has rattled the once-untouchable stature of the supreme leader with protesters openly defying his orders to leave the streets. Underscoring how the protesters have become emboldened despite the regime's repeated and ominous warnings, witnesses said some shouted "Death to Khamenei!" at Saturday's demonstrations - another sign of once unthinkable challenges to the virtually limitless authority of the supreme leader. Rafsanjani was deeply critical of Ahmadinejad during the presidential campaign and has the potential to lead an internal challenge to Khamenei. His daughter's arrest came as something of a surprise: In his Friday sermon to tens of thousands of worshipers, Khamenei had praised Rafsanjani as one of the architects of the revolution and an effective political figure for many years. Khamenei acknowledged, however, that the two have "many differences of opinion." Khamenei has accused foreign media of making "malicious" attempts to portray a schism among the ruling clerics. At Friday's prayers, he acknowledged that all four presidential candidates "have differences, but all of them belong to the system." Iran's regime continued to impose a blackout on the most serious internal conflict since the 1979 Islamic Revolution. But fresh images and allegations of brutality emerged as Iranians at home and abroad sought to shed light on a week of astonishing resistance to hardline Ahmadinejad and Khamenei. The New-York based International Campaign for Human Rights in Iran confirmed scores of wounded demonstrators who had sought medical treatment after Saturday's clashes were arrested by security forces at hospitals in the capital. It said doctors had been ordered to report protest-related injuries to the authorities, and that some seriously wounded protesters had sought refuge at foreign embassies in a bid to evade arrest. "The arrest of citizens seeking care for wounds suffered at the hands of security forces when they attempted to exercise rights guaranteed under their own constitution and international law is deplorable," said Hadi Ghaemi, spokesman for the campaign, denouncing the arrests as "a sign of profound disrespect by the state for the well-being of its own people." "The government of Iran should be ashamed of itself. Right now, in front of the whole world, it is showing its violent actions," he said. Amnesty International cautioned that it was "perilously hard" to verify the casualty tolls. "The climate of fear has cast a shadow over the whole situation," Amnesty's chief Iran researcher, Drewery Dyke, told The Associated Press. "In the 10 years I've been following this country, I've never felt more at sea than I do now. It's just cut off." Iran has imposed strict controls on foreign media covering the unrest, saying correspondents cannot go out into the streets to report. Reporters Without Borders said 23 journalists were arrested over the past week. The BBC said Sunday that its Teheran-based correspondent, Jon Leyne, had been asked to leave the country. The broadcaster said its office remained open. Newsweek said its journalist Maziar Bahari was arrested on Sunday morning and had not been heard from. Also Sunday, Iranian Foreign Minister Manouchehr Mottaki held a news conference where he rebuked Britain, France and Germany for raising questions about reports of voting irregularities. Mottaki accused France of taking "treacherous and unjust approaches." But he saved his most pointed criticism for Britain, raising a litany of historical grievances and accusing the country of flying intelligence agents into Iran before the election to interfere with the vote. The election, he insisted, was a "very transparent competition." That drew an indignant response from British Foreign Secretary David Miliband, who "categorically" denied his country was meddling. "This can only damage Iran's standing in the eyes of the world," Miliband said. German Chancellor Angela Merkel urged Iran anew to conduct a complete and transparent recount.