Kyiv said Friday the bodies of 77 soldiers had been returned to Ukraine, days after the downing of a Russian military plane threw doubt on the future of such exchanges.
It came as Moscow and Kyiv traded fresh accusations over a plane crash Russia says happened after it was shot down near the border with Ukraine, killing 65 Ukrainian prisoners of war.
While Kyiv has not outright denied Russia's claims, officials have appeared to question whether its POWs were really on board.
This latest repatriation of bodies appeared unrelated to the downing of the plane, which crashed in a fireball in Russia's western Belgorod region on Wednesday.
"Preparations for the repatriation had been underway for a long time," Ukraine's Coordination Headquarters for the Treatment of Prisoners of War said in a statement.
Hundreds of captured prisoners of war have been freed in dozens of exchanges throughout the near two-year war.
But Russia's claims that Ukraine shot down a plane ferrying its own POWs had thrown doubts on the future of such exchanges and repatriations.
On Friday, Ukraine was still disputing Russia's account of the crash of the Ilyushin 76 military transport plane.
The Kremlin dismissed the idea of releasing evidence proving that dozens of Ukrainian soldiers had been killed.
"Investigators are working, I have nothing to add on this topic," Kremlin spokesman Dmitry Peskov told reporters when asked if Russia planned to publish evidence showing Ukraine shot down the plane, and who -- or what -- was on board.
On Thursday, Russia's Investigative Committee published video footage of what it said was the crash site. It showed a small chunk of plane debris and blurred close-ups of a body.
On Friday, Ukraine's human rights ombudsman Dmytro Lubinets dismissed the material released so far by Moscow as "elements of an information propaganda campaign against Ukraine".
Both Kyiv and Moscow have opened criminal investigations, and Ukrainian President Volodymyr Zelensky has called for an international investigation.
On Wednesday, he accused Moscow of "playing with the lives" of Ukrainian soldiers and their families.
Kyiv has not confirmed or denied its involvement in the plane crash or said whether it was carrying its captured soldiers.
It confirmed that a prisoner exchange was due to take place later that day. But it said Moscow had not informed Kyiv that the soldiers would be transported to the border by plane, as it had done in the past.
Ukraine's army vowed to "continue" targeting Russia's military operations in the border area where the plane was downed, in a statement published hours after the incident.
