Shirin Ebadi (file photo)

International human rights groups and Nobel laureate Shirin Ebadi are urging Iran to free two Iranian-American academics charged with spying.

In a statement, the groups and Ebadi said Iran should immediately release from detention Haleh Esfandiari and Kian Tajbakhsh.

They also called on Iran to lift travel bans against two journalists - Iranian-American Parnaz Azima, who is also charged with spying, and French-Iranian Mehrnoush Solouki.

Ebadi says Iran's actions violate international norms. She says Iran's judiciary is denying dual-nationals their basic rights.

The rights groups - Amnesty International, Human Rights Watch, the International Federation for Human Rights and Reporters Without Borders -also want Iran to clarify the status of another Iranian-American, Ali Shakeri, who is believed to be in detention.

Haleh Esfandiari

The United States says it is preposterous for Iran to accuse Esfandiari, Tajbakhsh and Azima of spying. U.S. officials have repeatedly said they should be allowed to return to the U.S.

Esfandiari is the director of the Middle East Program at the Woodrow Wilson International Center for Scholars, a Washington-based foundation. She has been held in a Tehran prison since May 8.

Tajbakhsh is an urban planning consultant linked to the New York City-based Open Society Institute. He has been imprisoned in Tehran since May 11. Billionaire businessman George Soros established the institute to promote democracy and human rights.

Azima works for U.S.-funded Radio Farda and Iran has barred her from leaving the country.

Some information for this report was provided by AFP and Reuters.