Fiber-optic wires connected to a drone during a test flight in the Kyiv region in December. Global Images Ukraine/Global Images Ukraine via Getty Images Ukraine then began using them as well.

A new video shows how prolific jamming-resistant fiber-optic drones are becoming on the battlefields in Ukraine. There are wires scattered all over the place. On Friday, Ukraine's defense ministry ...

The coils vary depending on the drone. Some of the fiber-optic drones can travel over 15 miles and carry several pounds of explosives — which can devastate troop positions or armored vehicles.