STORY: Videos released by the Ukrainian secret service and the Russian defense ministry showed the prisoners returning from captivity.

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 that 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.