In New York Wednesday, Amnesty International and other human rights groups sponsored a vigil calling for the immediate release of detained Iranian-Americans by Tehran. In May, the government of Iran arrested four Iranian-Americans on accusations of harming national security. VOA's Sean Maroney reports from the vigil.

More than a hundred protesters rallied in the humid mid-day heat outside the United Nations, chanting for the release of prominent U.S. scholar Haleh Esfandiari from the notorious Evin Prison in Tehran.

Esfandiari's husband, Shaul Bakhash, was among the protesters.

"We know that interrogations at Evin Prison are not nice nor gentle. She needs medication. She needs medical attention. I think it's unconscionable that the authorities in Evin Prison keep her not only in prison but don't allow family visits or legal representation," he said.

Last month, the government of Iran arrested the 67-year-old Esfandiari, as well as three other Iranian-Americans, including scholar Kian Tajbakhsh, journalist Parnaz Azima and activist Ali Shakeri. Shakeri is now out of prison on bail but is not allowed to leave Iran.

Formal charges against the detainees have not been released, but the Iranian Intelligence Ministry reportedly charged Esfandiari, Tajbakhsh and Azima with "acting against state security by engaging in propaganda and espionage for foreigners."

Amnesty International's Zahir Janmohamed helped organize Wednesday's vigil. He says the detainees are pawns in a diplomatic game between the United States and Iran.

"Now I think when you couple that with sort of an overall paranoia in Iran, you have someone like Haleh Esfandiari - a very well-known, respected scholar - I think holding her is a way for them to sort of play a diplomatic game. There are Iranians held by the United States in Iraq, and I think this is seen as a tit-for-tat," he said.

Esfandiari, a naturalized U.S. citizen, was visiting her 93-year-old mother last December when Iranian officials took away her passport. U.S. officials have strongly denied that Esfandiari or the other detained Iranian-Americans were engaged in any espionage activity.

Iran's Intelligence Ministry claims that Esfandiari's and her fellow scholar Kian Tajbakhsh's professional activities, such as speaking at international conferences, are evidence of "acting against national security." It also accuses Parnaz Azima, a journalist with the U.S. government-funded Radio Farda, of spreading "propaganda against the Islamic Republic."

Esfandiari's daughter, Haleh Bakhash, says she hopes her mother will be released soon.

"I'm holding on to hope that my mother is thinking about her family everyday and about her friends and that that's giving her the strength to go on each day and that she knows in her heart that this is going to come to an end soon and that she will be sent home to be reunited with us," she said.

It is still unclear whether any of the accused will face trial.