Iran has released one Dane and two Austrian-Iranian citizens who had been detained in the country for several years.
The trio's release was announced by Austria and Belgium on Friday.
It was part of a prisoner swap in which Tehran got back an Iranian diplomat who has been convicted in Belgium on terrorism charges.
Austrian-Iranian citizens Kamran Ghaderi and Massud Mossaheb were released after 2,709 and 1,586 days, respectively.
The pair are now “on their way to Austria”, the country's foreign ministry said.
“I am very relieved that we can finally bring Karman Ghaderi and Massud Mossaheb home after years of arduous imprisonment in Iran,” said Austrian Foreign Minister Alexander Schallenberg.
“They are already on their way to Austria, where their families are eagerly waiting for them.
“Our years of diplomatic efforts to secure their release have borne fruit.”
He thanked Belgian Foreign Minister Hadja Lahbib and Omani Foreign Minister Sayyid Badr Al Busaidi for “their valuable support”.
Mr Al Busaidi expressed his delight on Twitter over a "positive", though undisclosed outcome, thanking Iran, Belgium and all contributors.
Belgium's Prime Minister Alexander De Croo said that he had informed the governments of Denmark and Austria of the release, which came a week after Tehran freed a Belgian aid worker in exchange for an Iranian diplomat who was convicted on terrorism charges.
“Belgium has successfully secured the release of two Austrians and one Dane who were unjustly held in detention in Iran,” said Hadja Lahbib.
Denmark’s Foreign Minister Lars Lokke Rasmussen said that he was “happy and relieved that a Danish citizen is on his way home to his family in Denmark after imprisonment in Iran”.
He did not name the person, saying their identity was “a personal matter” and he could not go into details.
Mr Rasmussen also thanked Belgium and said that Oman “played an important role”.
An Oman Royal Air Force Gulfstream IV, which had been on the ground in Tehran for several days, took off shortly before the announcement.
Mr Ghaderi, an Austrian-Iranian businessman, was arrested in 2016 and later sentenced to 10 years in prison for allegedly spying for the US – charges strongly rejected by his supporters.
Mr Mossaheb, also an Austrian-Iranian businessman, was arrested in 2019 and received a 10-year prison sentence after what Amnesty International called “a grossly unfair trial for vague national security offences”.
Amnesty had said Mr Mossaheb suffered from heart failure and diabetes, making his imprisonment much more dangerous for him.
Iranian state media and officials did not immediately acknowledge the release on Friday, which is part of the weekend in the country.
Iran has detained a number of foreigners and dual citizens over the years, accusing them of espionage and other state security offences.
Often those charged are sentenced following secretive trials in which rights groups say they have been denied due process.