Belarus has released five prisoners in a US-brokered deal involving Russia, officials said Tuesday.
In return, Moscow and Minsk secured the return of several people held in European countries, including the release of a prominent Russian archaeologist held in Poland.
The deal has been seen as a rare moment of diplomatic cooperation at a time when Western efforts, led by the United States, to mediate an end to Russia's war in Ukraine have stalled.
"It is the finale of a two-year-long, complex diplomatic game full of dramatic twists and turns," Polish Prime Minister Donald Tusk said on X.
US special envoy to Belarus John Coale said Washington had "helped secure the release" of three Polish citizens and two Moldovans who had been held in Belarus.
More than 500 political prisoners have also been released in Belarus after "more than a year" of joint negotiations, Coale said at a press conference with the Polish foreign minister.
Up to 900 remain behind bars in the country, he added.
Among those released is Andrzej Poczobut, a prominent Polish-Belarusian journalist and critic of Belarusian President Alexander Lukashenko.
The release was announced by Tusk, who wrote on X: "Andrzej Poczobut is free! Welcome home to Poland".
The 53-year-old journalist had been jailed since 2021 and was sentenced in 2023 to eight years in a penal labour camp. He had been working as Minsk correspondent for the Polish Gazeta Wyborcza daily and is also a member of Belarus's Polish minority.
The Belarusian opposition decried his arrest, calling it an act of "personal vengeance" by the president, and Poland has long demanded his release.
Poland's foreign minister Radoslaw Sikorski said the releases were part of an "international exchange" of detainees between several countries.
He confirmed that among those freed on the Polish side was a Russian historian arrested in Poland, who was facing extradition to Ukraine.
Russian state media identified the man as Alexander Butyagin, an archaeologist arrested last December and wanted in Ukraine for conducting excavations on Russian-occupied territory.
Speaking to Russian media, the country's security services (FSB) added he was freed along with another Russian citizen.
In good shape
American envoy Coale said seven countries apart from the US were involved in the exchange: Russia, Belarus, Kazakhstan, Romania, Poland, Ukraine and Moldova.
Belarus, a close ally of Russia, heavily repressed political dissent under Lukashenko after mass protests erupted in 2020 following a disputed presidential election.
Many opposition figures, activists and journalists were arrested in the aftermath, and many remain detained. Rights groups say prisoners are often held there on politically motivated charges.
Following Poczobut's release, Gazeta Wyborcza journalist Bartosz Wielinski posted a photo of himself and the freshly freed reporter in a car.
"The first kilometres of freedom," he wrote. "We're heading for Warsaw".
Poland's foreign minister later said he had spoken to Poczobut, adding on X that he was "exhausted but in good shape".
"All of Poland is rejoicing at his release," Sikorski said. "We do not abandon our own."