But as rallies failed to materialize, a female protestor reached by ABC News by telephone in Tehran complained about the lack of leadership.
Asked whether she is disappointed that the streets were so quiet, the female protestor, who did not give her name, said "yes."
"Of course it is! It's really sad. People getting killed, people doing everything in their power to go against the regime after 30 years and we don't have the support here. We don't have proper leadership," she said.
The government's official statement is that the protests, sparked by the disputed presidential election of June 12, are being carried out by terrorists with links to foreign powers.
Speaking today, President Mahmoud Ahmedinejad demanded the United States and Britain stop interfering in Iran, adding that the election proved most Iranians love the regime.
That claim is proving more and more far-fetched on the ground. Today, the government continued mass arrests, including journalists, expelling BBC correspondent John Leyne from the country.
American Michelle May, who was in Iran on vacation, was unwittingly caught up in the violence. She said she was abducted by paramilitary basij fighters, the most aggressive in battling the protesters, and said she was accused of being a spy.
"I thought, maybe I'll make a scene and they'll go away," May said. "But they didn't. They put me into their car."
"I couldn't believe what was happening to me," she said.
Before releasing her, police forced her to sign a confession.
Even though the streets were quiet, the political battle persists at the highest levels of the Iranian government.
Today, the daughter of former President Hashemi Rafsanjani, Mousavi's chief political backer, was arrested. And Ali Larijani, the powerful parliament speaker, directly challenged the ruling Guardian Council for ignoring the protesters' complaints.
Faezeh, Rafsanjani's daughter, had joined protest crowds on Saturday, a day after Iran's Supreme Leader Ayatollah Ali Khamenei reiterated that such demonstrations would be considered criminal.
"Ayatollah Khamenei is not tolerating anybody who criticizes his policy. The main thing that is common among those arrested is that they have criticized the Ayatollha Khamenei over the past 20 years -- his foreign policy, his domestic policy, his cultural policy," said Mehdi Khalaji, a visiting fellow at the Washington Institute for Near East Policy.
"The government wants to cut the head of this movement from its body by cutting off all sources of information," Khalaji said.
Stateside, Iranian Americans marched today in support of opposition leader Mir Hossein Mousavi's movement, from Los Angeles and New York to the president's front door.
In Washington, D.C., the president was monitoring the situation closely.
An administration source said President Obama has received intelligence updates throughout the day.
Analysts say that the Iranian elections have posed a delicate diplomatic balancing act for this administration. If the clashes continue between the Iranian regime and the protestors, Obama could be forced to take an even stronger stance, they say.