Russia on Wednesday accused Kyiv of shooting down a military transport plane, killing all 74 people on board including 65 Ukrainian prisoners of war.

The flight was on its way to the southern region of Belgorod ahead of a prisoner exchange at the border when it was brought down by a “terrorist act,” the Kremlin said.

NBC News could not independently verify who was on board the flight or what caused it to crash. Ukrainian officials cautioned against sharing “unverified information” but did not immediately deny the claims or offer further details.

The neighbors have traded conflicting accusations throughout the war, which is approaching the two-year mark.