A fun video of military doctors and nursing staff happily dancing to the tune of Pharrell Williams' hit song "Happy" has gone viral.

The video, said to be shot at 12 Air Force Hospital at Gorakhpur in Uttar Pradesh, shows a lady Group Captain leading the dance party.

It also shows doctors, patients and staff in uniform swinging to American rapper Pharrell Williams' song which goes like "It might seem crazy, what I am about to say, sunshine she is here, you can take a break...."

This is the second such video from the services to hit the internet. In 2013, a "Gangnam Style" video shot at the Defence Services Staff college in Wellington had gone viral.

It is, however, not clear when was this video from Gorakhpur shot.