This story was written for CBSNews.com by Bonnie Shelton and Faiza Virani with CBS News's Investigative Unit
CBS News has learned exclusively that members of the Basij have been instructed to shave off or shorten their beards.
According to Mohammad, a 45 year-old resident of Tehran who wished to protect his identity, the new tactic is an effort to conform to the appearance of ordinary citizens in order to blend in with protestors.
In addition, he says that Radio Farda, a Persian language radio station based in the Czech Republic broadcasting to Iran has been closely monitoring the situation. During an interview with participants, they have urged the Revolutionary Guard, a hard line security force, to stop killing their Iranian brothers. The radio address further urges the militia to stop attacks on innocent civilians and to not blindly obey the orders of their superiors.
Iranian demonstrators have expressed their frustration at the government by "destroying ATM machines, bus stops and phone booths," said Mohammad in an interview with CBS News .
In the days since the election results were announced, demonstrators have flooded the streets of Tehran protesting the election's outcome, prompting Supreme Leader Ayatollah Ali Khamenei to announce on Friday that further protests will be met with dire consequences.
According to Mohammad, "Areas potentially exposed to demonstrations have closed down earlier than usual, resulting in traffic dying down and stores closing early, at 7 p.m. rather than 10 p.m.," in order to protest the current state of affairs and out of fear of police retaliation.
But Mohammad tells CBS News that many of the streets of Tehran have quieted over the past few days, as "residents remain cautious" and more on edge.
Even those who are not protesting have become targets of the undercover police, known as the Basij, who have been chasing protestors into homes and businesses in order to punish those who try and help demonstrators.
"The undercover police are bearded individuals dressed as civilians in plain clothes and wearing vests. They are helping riot police without taking responsibility for the beatings," he says.
The undercover police are also attempting to create confusion by destroying storefronts and damaging property and blaming the violence on demonstrators.
Mohammad reports of instances where the Basij have thrown rocks at the windows of homes that house demonstrators as well as threatening violence against anyone who protects a protestor trying to escape punishment.
Although the streets may be less crowded and shops closed down, Mohammad reports that "the protestors have not backed down and the sounds of unrest have increased over the past week."
He says there has been an increase in chants of "Allah-u-Akbar" meaning "God is great", "Down with the Dictator" and
"Down with Khomeini" that can be heard in the streets after dark along with peoples' violent screaming. These slogans gain momentum each time members of the Revolutionary Guard make a statement attacking the protesters.
Mohammad says that despite the Supreme Leader's warnings, protestors "continue to gather in small groups throughout the night in order to make their voices heard."
But opposition leader Mir Hossein Mousavi urged on the peaceful protests saying Monday "The country belongs to you" and "Protesting lies and fraud is your right."
By Bonnie Shelton and Faiza Virani with CBS Investigates