Russia on Wednesday released 10 foreign prisoners of war captured in Ukraine following mediation by Saudi Crown Prince Mohammed bin Salman, the Saudi foreign ministry said.

The freed prisoners were American, British, Croatian, Moroccan and Swedish nationals, the ministry said in a statement, adding that a plane carrying the prisoners landed in the kingdom.

“The relevant Saudi authorities received and transferred them from Russia to the kingdom and are facilitating procedures for their respective countries,” the statement said.

The ministry did not identify the prisoners. A Saudi official said they were five Britons, two Americans, a Croatian, a Moroccan and a Swedish national.

British Prime Minister Liz Truss hailed the release of the British nationals on Twitter as “hugely welcome news” after “months of uncertainty and suffering for them and their families.”

British lawmaker Robert Jenrick said Aiden Aslin was among those released. He was captured earlier this year then sentenced to death by a court in the self-proclaimed Donetsk People’s Republic (DPR), one of Russia’s proxies in eastern Ukraine.

Russia also released U.S. citizens Alexander Drueke, 39, and Andy Huynh, 27, a family representative told Reuters on Wednesday.

The pair, both from Alabama, were captured in June while fighting in eastern Ukraine where they went to support Ukrainian troops resisting Russia’s invasion.

Large numbers of foreigners have travelled to Ukraine to fight since Russia’s Feb. 24 invasion. Some of them have been caught by Russian forces, along with other foreigners in the country who say they were not fighters.

Reuters could not immediately establish if the released group included Britons Shaun Pinner and Morocco-born Brahim Saadoun who were also captured and sentenced to death in Donetsk.

A Swedish citizen, captured at the port city of Mariupol and facing a possible death sentence under the laws of the DPR, was among those released, Swedish Foreign Minister Ann Linde confirmed.

“I can confirm that the Swede who in May was taken into custody by Russian forces is free and on his way to Sweden,” Linde told Swedish news agency TT on the sidelines of the United Nations General Assembly in New York.

Prince Mohammed has maintained close ties with Russian President Vladimir Putin, including within the framework of the OPEC+ oil producers group, despite heavy pressure from Washington, Riyadh’s traditional ally, to isolate Russia.

Both Ukrainian and Russian forces have captured hundreds of enemy fighters since the start of the conflict, with a handful of prisoner exchanges having taken place.

The head of the U.N. human rights mission in Ukraine said earlier this month that Russia was not allowing access to prisoners of war, adding that the U.N. had evidence that some had been subjected to torture and ill-treatment that could amount to war crimes.

Russia denies torture or other forms of maltreatment of POWs.