New Delhi: Iran and the United States exchanged prisoners on Monday in a rare deal between the arch enemies that also unfroze $6 billion of Tehran's funds, reported news agency Reuters. Under the deal, five detained American-Iranian dual nationals were released by the Islamic Republic and flown to Qatar, while the US also freed five Iranians from American prisons. 


A plane sent by mediator Qatar flew the five US citizens and two of their relatives out of Tehran soon after both sides received confirmation the funds had been transferred to accounts in Doha, a source briefed on the matter told Reuters.


At the same time, two of the five Iranians landed in Qatar, a US official said. Three have opted not to return to Iran.


Earlier in the day, Iran's Foreign Ministry spokesperson Nasser Kanaani had said the funds, which had been frozen in South Korea, would be in Iran's possession on Monday so the deal mediated by Qatar during months of talks could go ahead, reported Reuters.


According to the Iranian Foreign Ministry spokesperson, two would return to Iran while two would stay in the US at their request. One detainee would join his family in a third country, he added.


An individual with direct knowledge of the deal told Reuters, "Both parties have been notified by Qatar that all $6 billion has been transferred from Switzerland to bank accounts in Qatar."


"A Qatari aircraft is on standby in Iran waiting to fly five soon-to-be-released US citizens and two relatives to Doha on Monday morning."


The announcement by Kanaani comes weeks after Iran said that five Iranian-Americans are now under house arrest as part of a confidence-building move while Seoul allowed the frozen assets, held in South Korean won, to be converted into euros. That money was then sent to Qatar, an interlocutor between Tehran and Washington in the negotiations.


The deal, which was first made public on August 10, will remove a major irritant between Washington and Tehran, although the two sides remain deeply at odds over issues ranging from Iran's nuclear ambitions and its influence around the region to US sanctions and America's military presence in the Gulf.


South Korea's Foreign Ministry had said on Monday it was working with all parties on the deal "to ensure smooth progress of all procedures so that it will be resolved once and for all."