Tehran, Iran (CNN) -- Reports conflicted Monday over the fate of Iranian opposition leaders Mir Hossein Moussavi and Mehdi Karrubi, with an opposition website reporting that they were in custody of the government but a semi-official news agency denying it.
The website, Kaleme, citing "trusted sources," reported Monday that the men and their wives had been arrested and taken to Tehran's Heshmatieh prison.
But the Fars News Agency, citing a source within Iran's judiciary, denied the report. The source, who was not identified, said that both men were inside their homes "and the only restrictions placed on them are contacts with suspicious elements."
Another Iranian source gave a similar account, saying the report of the men's imprisonment was false.
Meanwhile, a Tehran resident said people in his neighborhood were chanting from inside their homes "God is great," a phrase used by the opposition movement after the disputed presidential elections in 2009.
The conflicting reports came shortly after the semiofficial news Fars News Agency reported that the government had restricted the movements and communication of both opposition leaders.
Referring to the opposition movement, Iranian Prosecutor General Gholam-Hossein Mohseni-Ejei said, "The movements and telephone communication of the head of rioters have been restricted and, if circumstances demand it, the next steps for arresting them and putting them on trial will be arranged," Fars reported.
"Today, these men no longer have a place amid the people," Mohseni-Ejei said, according to Fars News.
In their stories, neither the official Islamic Republic News Agency nor Fars named the two opposition leaders.
The opposition has called for a demonstration to be held Tuesday to protest the imprisonment of Karrubi and Moussavi.
Over the weekend, before the fate of the couples was known, the International Campaign for Human Rights in Iran expressed concern for their safety.
"Moussavi and Karrubi and their wives have been disappeared; they are being held incommunicado in an unknown location, a severe breach of Iranian and international law," Aaron Rhodes, a spokesman for the human rights group, said in a statement.
"Given the lynch mob-like calls for their execution by numerous Iranian politicians and clerics, there is reason to be deeply concerned for their safety and well-being," Rhodes said.
State-run Press TV aired video of Iranian lawmakers earlier this month chanting, "Moussavi, Karrubi ... execute them."
This month, Iranian authorities began rounding up a number of government opponents amid calls for protests like those that have swept across North Africa and the Middle East.
Iranian government leaders have praised the revolution that overthrew Egyptian President Hosni Mubarak, but when protesters took to the streets of Tehran on February 14, the government cracked down hard. The Iranian government rounded up activists ahead of the protests after Karrubi and Moussavi called for supporters to gather at Azadi Square, the site of mass protests by Iran's opposition movement after the disputed 2009 presidential elections.
Despite the security crackdown, tens of thousands of demonstrators marched in Tehran. Dozens of demonstrators were detained during those protests, while videos posted on YouTube showed others had been chased and beaten.
Two people were killed during the protests, according to Fars. Several others were seriously wounded as a result of the gunfire, which the Iranian government blamed on "agitators and seditionists."
An Iranian government source said Saturday that Iranians were disturbed by the opposition's demonstrations.
"The people are not happy with these protests and (Moussavi and Karrubi) making announcements for more protests. The people believe their peace is being disrupted, and they want these protests to stop," the source said.
U.S. Secretary of State Hillary Clinton on Wednesday accused Iran of recently cracking down on protesters and political opponents, and security forces of killing peaceful demonstrators.
International journalists have been limited in their ability to gather news in Iran, where the government has squelched the media and maintains tight control over state-linked news organizations. During the protests this month, foreign journalists were denied visas, accredited journalists living in the country were restricted from covering the demonstrations, and internet speeds were slowed to a crawl in an apparent attempt to restrict information being transmitted abroad.
CNN's Reza Sayah and Michael Martinez contributed to this story.