The Ukrainian president's chief of staff, Andriy Yermak, said 116 Ukrainians had been returned, while Russian news agencies cited Moscow's defence ministry as saying 63 Russian POWs had been freed.

"We managed to return 116 of our people, defenders of Mariupol, partisans from Kherson, snipers from the Bakhmut (front) and other heroes of ours," Yermak wrote on Telegram.

President Volodymyr Zelenskiy said in a video address that since the war started last February, Ukraine had secured the release of 1,762 men and women from Russian captivity.

Yermak also said the bodies of British volunteer aid workers Andrew Bagshaw and Chris Parry had been sent back to Ukraine.

Bagshaw and Parry were killed during an attempted humanitarian evacuation in eastern Ukraine in January, Parry's family has previously said.

Russia's Defence Ministry said the released Russian servicemen included "sensitive category" persons, whose exchange was made possible through the mediation of the United Arab Emirates (UAE), according to agencies.