Iranian state media reported on Thursday that American inmates had been transferred out of Tehran's Evin prison as part of a prisoner swap deal with the United States.
"Based on the agreement, five Iranian prisoners in the US and five American prisoners in Iran will be exchanged," the official IRNA news agency reported, quoting an informed source.
Earlier, US sources said that American prisoners Siamak Namazi, Emad Sharqi and Morad Tahbaz, along with an unidentified fourth American, have been moved from Evin jail to an undisclosed house.
The sources said a fifth American whose case was also part of the discussions had already been moved in recent
weeks to house arrest.
All of the detained Americans are of Iranian descent, but Iran does not recognise dual nationality.
IRNA quoted the Islamic republic's mission at the United Nations as confirming the news.
It reported that the deal with the US includes releasing an amount of $6 billion of Iranian money frozen in South Korea, along with a "significant amount of Iranian funds in Iraq's TBI bank".
It added that the process had begun to also release Iranian funds in a European bank.
"The (prisoners') exchange will not take place until the released money is deposited into the accounts sought by Iran," IRNA said quoting the "informed source".
The progress on the prisoners -- one of whom has been detained for nearly eight years -- comes after quiet, exhaustive diplomacy between the longtime adversaries whose separate talks on restoring a nuclear deal broke down.
Tehran and Washington cut diplomatic ties in 1980 following the Islamic revolution in Iran. Tensions heightened after the then US president Donald Trump withdrew from the nuclear deal in 2018.
The United States has since reimposed biting sanctions on Tehran, prompting the latter to step away from many of the nuclear commitments it made under the accord.
pdm-mz/srm