Armenia and Azerbaijan have been in a state of conflict for several decades over the disputed Nagorno-Karabakh region, but a deluge of grisly video released by the combatants in recent days shows that it's now being fought in a newer high-tech — and highly lethal — fashion.

One particularly startling video seems to show Armenian soldiers desperately firing into the sky as an ominous buzzing sound increases in pitch like a German World War II dive bomber. Seconds later, a drone plunges into the roof of a bus, its 50-pound warhead consuming the vehicle in a ball of fire.

It's just an example of how armed drones, or Unmanned Combat Air Vehicles — UCAVs — in military speak, are upping the casualties in long-simmering regional conflicts that until now have been low-level — limited in large part by smaller countries' inability to make precision strikes on forces at and beyond the front line.