Yet another American citizen has disappeared in Iran and is feared to be in detention, according to Human Rights Watch, a nongovernmental organization based in New York.
Ali Shakeri, an Iranian-American dual citizen, was scheduled to leave Iran May 13, but "he disappeared from the radar," Human Rights Watch's Hadi Ghaemi told ABC News.
Ghaemi has been in touch with Shakeri's associates, who say that the political activist and writer from Irvine, Calif., was in Iran to visit his mother who died while he was there.
According to a statement released by Human Rights Watch, those associates believe Shakeri is "being detained by Iranian authorities."
"The Iranian government has not provided any public information about his whereabouts," the statement continued.
If Shakeri is detained, he would be the third Iranian-American to be held by Iran in recent weeks, in addition to others who have been prevented from leaving the country.
The U.S. State Department could not confirm that Shakeri was missing or detained, but deputy spokesman Tom Casey said, "We are concerned by the fact that there appears to be a pattern here of harassment against private citizens and against private Iranian-Americans. And that's something that I guess the Iranians will have to offer an explanation for."
Shakeri is the latest in a series of apparent arrests by the Iranian government of Iranian-American scholars in the country. The cases fit a similar pattern of dual citizens being arrested in Iran.
A scholar with the Woodrow Wilson International Center for Scholars, Haleh Esfandiari was sent to Iran's Evin Prison May 8 after living for months under house arrest. The United States has requested consular access to Esfandiari through the Swiss Embassy in Tehran, which is the usual channel of communications since the United States and Iran severed diplomatic ties almost three decades ago. But the United States has has not yet received a response.
Kian Tajbakhsh, a former professor at the New School for Social Research in New York who was in Iran with the Soros Foundation's Open Society Institute, was detained in Iran on or around May 11. The State Department's Casey said today that the United States would soon request consular access for Tajbakhsh.
Parnaz Azima, a journalist with Radio Farda, a partially U.S.-funded radio station that broadcasts in Iran, had her passport taken from her by Iranian authorities and has been prevented from leaving the country.
Another Iranian-American woman had her passport taken from her in recent weeks, but sources say she has since had it returned has been able to leave the country.
A former FBI agent has also been missing in Iran for several months. Robert Levinson was last seen on Iran's Kish Island when he disappeared and has not been seen or heard from since. Iran authorities responded to inquiries about Levinson by saying they have no knowledge of his whereabouts. Sources tell ABC News, however, that the United States believes Levinson is still in Iranian custody.
According to Casey, the United States does not plan to raise the subject of the detained Americans during an historic meeting with Iran planned for next Monday. For the first time in decades, the United States and Iran will hold high-level talks in Baghdad between the U.S. ambassador to Iraq, Ryan Crocker, and Iranian officials.
Casey said that that meeting would focus exclusively on issues related to Iraq. The United States accuses Iraq of fomenting sectarian violence in Iraq by providing munitions and training to armed groups in an effort to destabilize the country and attack U.S. troops.