In an open letter to world leaders, human rights organizations and the media, the families of six political hostages held in Iran are asking for all governments to help secure the release of their loved ones.

Demonstrators holding a poster and signs (© Virginie Salmen/AFP/Getty Images)
Supporters demonstrate in Quebec, Canada, in 2012 for the release of Saeed Malekpour, 35, a Canadian-Iranian software engineer held hostage in Iran since 2008. (© Virginie Salmen/AFP/Getty Images)

“We come from many countries, with different backgrounds and different perspectives, but we have banded together now to come to you as one voice,” the family members of dual nationals and foreign nationals taken hostage in Iran said in their December 3 letter.

"Kidnapped" poster with three photos of Robert A. Levinson (© Manuel Balce Ceneta/AP Images)
This FBI poster from 2012 of Robert Levinson shows, from left, Levinson before he was kidnapped, an image from a video released by his kidnappers and an image after he had spent five years in captivity. (© Manuel Balce Ceneta/AP Images)

The families have met with each other and United Nations officials to share the striking similarities of each of their loved ones’ cases, including long prison sentences on trumped-up charges of espionage, forced confessions under torture, and harsh physical and psychological abuse while imprisoned. None have received a fair trial.

“Each story is not just a case of arbitrary detention, but deliberate and tactical moves by the Iranian authorities to secure bargaining chips,” the families wrote.

Hostage taking has been a constant and contemptible feature of the Iranian regime for decades. Foreigners who come to Iran to work, study or visit family are frequent targets for the regime, who see them as opportunities to extract money or policy changes from governments.

Since the U.S. citizen Bob Levinson was kidnapped in Iran in 2007, more than 50 people with some connection to a Western power have been taken hostage by the Iranian authorities, and as many as 20 are still held hostage in Iran, the families wrote.

Nikki Haley at U.N. microphone with flags in the background (© Mary Altaffer/AP Images)
U.S. Ambassador to the United Nations Nikki Haley (© Mary Altaffer/AP Images)

“Please clearly and immediately join with us to tell the government of Iran that this behavior will no longer be accepted and must end now,” the letter ends. It is signed by the families of Robert Levinson, Nizar Zakka, Saeed Malekpour, Kamran Ghaderi, Ahmadreza Djalali and Baquer and Siamak Namazi “and the many more families who remain silent in fear for the safety of their loved ones.”

U.S. Ambassador Nikki Haley called Iran’s practice of taking hostages “just another example of Iran’s violations of international norms.”

“Iran invented reasons to throw these innocent people in jail and keeps them there with no end in sight and no fair judicial process for them to pursue,” she said as she released the families’ letter. The hostages “should be released immediately and returned to their families. We won’t rest until they are,” Haley said.