The IL-76 plane was travelling from an air base near Moscow to the border city of Belgorod when it was struck by anti-aircraft missiles, killing all on board, the defence ministry said.

"At 11:15 am (0815 GMT) today, the Ukrainian regime in Kyiv committed a terrorist act by shooting down a Russian military transport aircraft," it said.

"The aircraft was shot down by the Ukrainian army from the village of Lyptsi in the Kharkiv region using an anti-aircraft missile system," it continued.

Two Ukrainian missiles were detected by Russian radar systems in the attack, it said.

"The Ukrainian leadership was well aware that, in accordance with established practice, the Ukrainian servicemen to be exchanged would be transported by military transport aircraft to Belgorod aerodrome today," it said.

"According to an earlier agreement, this event was to take place in the afternoon at the Kolotylivka checkpoint on the Russian-Ukrainian border," it continued.

Russia said that Ukraine had "disregarded the lives of its own citizens" in the attack.

Ukrainian rights ombudsman Dmytro Lubinets, who is among officials responsible for prisoner exchanges, said his office was investigating.