An 18-year-old mechanical engineering student has attracted the attention of over 2 million viewers when he uploaded a video on YouTube showing a handgun mounted on a multirotor firing shots even without a human being pulling the trigger.

The video has also attracted the attention of the US government, particularly the Federal Aviation Administration (FAA), which said it will launch a probe on the viral video.

"The FAA will investigate the operation of an unmanned aircraft system in a Connecticut park to determine if any Federal Aviation Regulations were violated," the agency, which is the US government's national aviation authority, said in a statement on Tuesday.

The FAA also said it will work with law enforcement agencies "to determine if there were any violations of criminal statutes" committed in the making of the viral video.

College student Austin Haughwout uploaded the 14-second video on YouTube entitled "Flying Gun."

The video showed a "homemade multirotor with a semiautomatic handgun mounted on it." The gun fired four shots before the unmanned aircraft landed at a grassy area.

Austin's father, Bret, immediately came to his son's defence, saying the unmanned aircraft shown in the video was not a drone, but only a remote-controlled toy.

"People have been playing with RC (remote-controlled) toys for many decades," the father said.

"The proper name for this is an RC quadcopter. The media keeps using the inappropriate word because it helps you to generate fear," he added.

He further said that people should not make "such a big deal" out of the video uploaded by his son on YouTube.

"It's not like it's anything new... He [Austin] is a mechanical engineering student. He builds all different kind of things," the father said.

Peter Sachs, an advocate for the safe and responsible use of drones in civilian life, maintained, however, that what Austin built is "a drone in every sense of the word."