RIYADH (Reuters) - Russia on Wednesday released 10 foreign prisoners of war in Ukraine, including five Britons and two Americans, in a Saudi-brokered prisoner exchange agreement, the Saudi foreign ministry said.

The ministry stated in a statement that the list of prisoners included citizens of the United States, the United Kingdom, Sweden, Croatia and Morocco, and said that a plane carrying the prisoners had landed in the Kingdom.

And the ministry added, "The concerned authorities in the Kingdom received them and transferred them from Russia to the Kingdom, and worked to facilitate the procedures for their return to their countries."

On Wednesday, Russia released 215 Ukrainians captured after a protracted battle in the port city of Mariupol earlier this year, including senior military leaders, a senior Ukrainian official said.

Among the released Ukrainian prisoners were the commander and deputy commander of the Azov battalion, which fought most of the fighting, said Andrey Yermak, chief of staff to President Volodymyr Zelensky.

Russia also released US citizens Alexander Druki, 39, and Andy Hyun, 27, a representative from the family of one of them told Reuters on Wednesday.

Drake and Hyun, both from Alabama, were captured by Russia in June while fighting in eastern Ukraine where they traveled to support Ukrainian forces resisting a Russian invasion.

US National Security Adviser Jake Sullivan and Secretary of State Anthony Blinken welcomed the release of the US citizens and thanked the Ukrainian government and Saudi Crown Prince Mohammed bin Salman for their role in releasing the prisoners.

British Prime Minister Liz Truss also welcomed the release of the British nationals, writing on Twitter "we warmly welcome this news" after "months of uncertainty and suffering for them and their families".

British Member of Parliament Robert Jenrick said Eden Aslin was among those released. He was arrested earlier this year and sentenced to death by a court in the self-proclaimed independent Donetsk People's Republic, among those fighting Russia's proxy in eastern Ukraine.

A large number of foreigners have traveled to Ukraine to fight since the start of the Russian invasion on February 24. Russian forces arrested some of them along with other foreigners in the country who said they were not combatants.

Saudi media reported that the Moroccan-born Briton, Ibrahim Saadoun, was among those who were released, and that a death sentence had been issued against him along with the British Aslin.

Swedish Foreign Minister Anne Linde confirmed that a Swedish citizen, who was captured in the port of Mariupol and faces a possible death sentence under the laws of the Donetsk People's Republic, is among those released.

"I can confirm that the Swede who was detained by Russian forces in May 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.

Saudi Crown Prince Mohammed has close relations with Russian President Vladimir Putin, including the two countries' cooperation within the framework of the OPEC + group of oil producers, despite intense pressure from Washington, a traditional ally of Riyadh, to isolate Russia.

Hundreds of enemy fighters have been captured by Ukrainian and Russian forces since the beginning of the conflict, but the two sides have exchanged only a few prisoners.

The head of the United Nations human rights mission in Ukraine said earlier this month that Russia does not allow contact with prisoners of war, adding that the United Nations has evidence that some of them have been subjected to torture and ill-treatment that may amount to war crimes.

Russia denies that prisoners of war are tortured or otherwise ill-treated.