Ukraine and Russia traded almost 200 prisoners of war in a swap announced separately by both sides on Saturday.
A video uploaded on social media by Ukrainian authorities on Saturday purported to show the Ukrainian released prisoners returning on buses and posing for pictures upon their arrival.
Reuters was not able to independently verify the date the video was filmed or the location of the footage.
Also on social media, the Ukrainian president's chief of staff, Andriy Yermak, said 116 Ukrainians had been returned, while Russian news agencies cited Moscow's defense ministry saying 63 Russian POWs had been freed.
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 Defense Ministry said the released Russian servicemen included "sensitive category" persons, whose exchange was made possible through the mediation of the United Arab Emirates, according to agencies.