According to Ukraine's "Strana.ua" news network, a video released by the General Intelligence Bureau of the Ministry of National Defense of Ukraine on the 25th showed that Ukraine used drones to launch attacks on Russian targets in Crimea, and two An-26 transport planes were hit.

Image from the video released by the Ministry of Defence of Ukraine on December 25

At the time of the announcement, there was no response by Russian officials to the Ukrainian claim.

Source: World Wide Web/Zhang Jiangping