In May 2018, the Belarus military tested a UAV with a rocket launcher attached, and a video of the demonstration was uploaded on YouTube. The drone rocket launcher was equipped with an RPG-26, a disposable anti-tank weapon that was first developed by the Soviet Union in the 1980s. The weaponized UAV and other military-adapted drones can be seen in this video:
The video showed the drone lifting off and firing a single round. Even after the quadcopter launched a rocket towards an unknown target, the UAV was still stable.

Screenshot from ВоенТВ Беларуси’s YouTube video.
According to Popular Mechanics, the video was taken on May 18 at the Losvido Training Ground in Belarus.