Cries of "Allahu Akbar" are clearly heard around Tehran by night
The Iranian authorities' clampdown on protests against the presidential election results means real danger for those still prepared to demonstrate - as well as for those who may have been noticed doing so already.
The BBC cannot independently verify the factual content of emails it receives, but the separate accounts create a picture of the Iranian authorities regaining control of the streets through fear and violence.
One man, who sent video of pro-reform demonstrations in Tehran to the BBC earlier this week, emailed again to say he had been detained by Basiji forces on Wednesday evening.
"I was arrested and beaten for about six hours from 1830 to 0100 and then they left me in a place outside Tehran...," he wrote. He added he was tired, but "still standing for freedom and democracy".
How can they claim they are not killing anyone?
Mohammed from Tehran emailed BBC Persian TV to report what he saw on Wednesday evening.
"At about 1730 in front of Sa'di metro station, plain clothes officers were shooting, and I myself saw four people die. I was lucky to get away unharmed. How can they claim they are not killing anyone?" he wrote.
He said he thought many people were being killed, wounded and arrested but they were all "taken away by plain clothes officers... there is no trace left of them, and obviously no news agency can report this".
A student who was tweeting regularly on the protests in Tehran has started posting again for the first time since Sunday:
• I'm only posting this to say I'm still alive & not in Tehran, I had a bad incident with Basij and couldn't use computer
• Shayan's brother's fate is still unknown, Reza has been released yesterday & at hospital right now & I think Masood is safe
• as soon I can walk properly again, I will go back to Tehran
• I will Tweet again at night, my back & neck hurts a lot & I can't sit here anymore
Others fear that they may be next on the Revolutionary Guards' hit list. Ahmed from Mashad emailed to say his earlier public involvement in Mehdi Karoubi's campaign now meant he was at risk.
"These times are very critical for us. I am clearing my home and hiding everything: my computer and mobile phone. We think when the street marches stop they will start to arrest us. Who knows? Maybe today, tomorrow, or over the next weeks," he wrote.
"The time of infinite horror is starting to rise up. So please don't call me again."
'Wandering the streets'
For many, the safest way to express their opposition is by shouting the former revolutionary chant, "Allahu Akbar" [God is great] from their rooftops at night.
Neda, from Esfahan, emailed BBC Persian TV in English, to warn that this carried risks too.
"We say Allahu Akbar every night. But they find the people who say this. They attack people's houses and capture them.
"The Islamic Republic of Iran's army has captured 12 protesters in Esfahan and now they are deciding whether to execute them.
Kaveh, who sent in the footage at the top of the page, repeats a similar story from Tehran. He said the chanting was "louder than ever" on Wednesday evening, but Basijis were "wandering the streets and looking up at buildings to find out where the chanting is coming from".
Many people complain of propaganda in state-controlled media. The Farsi on the photo above, emailed to BBC Persian, ridicules the running order of TV news bulletins:
• Somebody's ankle was twisted in Somalia.
• Cooking oil will be distributed with Coupon number 527.
• Middle East's largest chewing gum factory opened.
• A baby panda was born in South Korea.
Another email to BBC Persian reports that Iranian news is claiming Israelis killed Neda Agha Soltan, the woman who was shot dead in Tehran protests on Saturday.
"If we assume this is true and Israelis have killed about 27 people so far, then why are they charging us huge sums of money in "bullet fees" to return the bodies? If the Israelis shot the bullet, why are you charging us for it?
Other emails to the BBC show some people think foreign powers are behind the unrest.
Jalal, from Tehran, warned: "Don't interfere in our internal affairs. You don't know Iranian people well. They may argue among themselves but they don't tolerate foreign interference."
Sima emailed from Tabriz to accuse Britain of stirring up trouble for its own ends. "Brits are egging on the rioters in Iran to divert attention from their own failed economic state."
Finally, Mohd Hussain Jafari, emailed from Tehran with the official government line:
"Once again, Iranians have proved their loyalty to the supreme leader of the revolution, but America and their colleagues got jealous and tried to interfere. Believe in the Almighty and surely America and others who try to violate the Islamic system will face defeat in the near future. Inshallah."
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