DONETSK, May 21. /TASS/. Russian military personnel are using fiber optic drones with a range of up to 50 km, the acting commander of a technical maintenance unit of the Russian Battlegroup East’s 29th Army, call sign Rezets, told TASS.

"Factory-made spools, for example, have cables 50 km long; 50 km is used, but the standard cable length on spools is generally 5 to 25 km," the commander said.

He added that the fiber optic cable length varies depending on the nature of the combat mission of an unmanned aerial vehicle’s operator.