Iran releases 4 US prisoners

Amid contentious US-Iranian relations, Iranian state television announced the release of four dual-nationality prisoners.

The Saturday report did not identify the prisoners but it comes amid speculation that jailed Washington Post bureau chief Jason Rezaian, a dual Iran-US citizen who was convicted of espionage in a closed-door trial in 2015, could be among them.

A report by the semi-official ISNA news agency quotes a statement from the Tehran prosecutor's office as saying the inmates were freed "within the framework of exchanging prisoners," without elaborating.

The US would not immediately confirm the Iranian report. Washington Post spokeswoman Kris Coratti told the AP that she could not confirm any change in Rezaian's case.

Iran was known to be holding four Americans. It was unclear who was being released, but here's who the four were:

Jason Rezaian, 543 days in prison

Jason Rezaian, the Post's Tehran bureau chief since 2012, was arrested along with his wife and two photojournalists on July 22, 2014. All were later released except for Rezaian.

On November 22, 2015, an Iranian court sentenced Washington Post reporter Jason Rezaian to prison.

Among the charges, Rezaian was accused of "collaborating with hostile governments" and disseminating "propaganda against the establishment", according to a statement from Rezaian's attorney, the Washington Post reported in April.

In the indictment, Iranian authorities said Rezaian had written to US President Barack Obama and called it an example of contacting a "hostile government", the Post said.

Former US Marine Amir Hekmati, 1,601 days in prison

Former Marine Amir Hekmati of Flint, Michigan served honorably during Operation Iraqi Freedom and was detained in August 2011 on espionage charges. His family says he has lost significant weight and has trouble breathing, raising fears he could contact tuberculosis.

Hekmati went to Iran to visit family and spend time with his ailing grandmother. After his arrest, his family says they were told to keep the matter quiet. He was sentenced to death in 2012. After a higher court ordered a retrial, he was sentenced in 2014 to 10 years in prison.

Pastor Saeed Abedini, ~1,218 days in prison

Pastor Saeed Abedini of Boise, Idaho was detained for compromising national security, presumably because of Christian proselytizing, in September 2012. He was sentenced in 2013 to 8 years in prison.

Obama met his wife and children in 2015. There are claims he was beaten in Iranian prison.

Abedini was previously arrested in 2009 and released after promising to stop organizing churches in homes. At time of arrest, was running an orphanage in Iran.

Siamak Namazi, 93 days in prison

Siamak Namazi, who is believed to be in his 40s, is a businessman and the son of a former governor in the oil-rich Iranian province of Khuzestan, The Atlantic reports.

head of strategic planning at the Dubai-based Crescent Petroleum, was visiting Tehran at the time of his arrest on October 15 from his family's home by security agents.

Namazi, the son of a former governor in the oil-rich Iranian province of Khuzestan, comes from a prominent Iranian family. Namazi's family came to the United States in 1983 when he was a boy, and he later returned to Iran after graduating from college to serve in the Iranian military. He has consulted on business opportunities in Iran for more than a decade.

Separately, Robert Levinson disappeared in Iran in 2007 while working for the CIA on an unapproved intelligence mission. American officials are unsure if the former FBI agent is even still alive. Iranian officials deny knowing where he is. Levinson traveled to Kish island and checked into hotel, purportedly investigating cigarette smuggling. He met US fugitive Dawud Salahuddin, the last man known to see him.

The CIA family paid Levinson's family over $2 million and some staffers lost their jobs over his unauthorized work. A proof of life video surfaced in 2011, saying he was held by a group. His family received photos that year, too, of Levinson bearded, shackled, wearing orange jumpsuit and holding signs in broken English. He has seven children. He suffers from diabetes and high blood pressure.

The Obama administration says the Americans come up in every conversation with the Iranians.