MOSCOW, April 21. /TASS/. Ukrainian UAV crews in Lithuania may pose a threat to Russia's security, a source in the Russian law enforcement agencies told TASS.

"Lithuanian mercenaries in the Armed Forces of Ukraine, and even more so instructors, do not play any role in the course of hostilities. But the presence of the Ukrainian military personnel, among whom, for sure, there are UAV crews, on Lithuanian territory, poses a threat to Russia's security," the source said.

Earlier, the Lithuanian army said that, as part of cooperation with the Ukrainian army, they were receiving "combat experience" training from the Ukrainian troops. The permanent presence of Ukrainian personnel in the Baltic republic was also confirmed.