Residents from across the city and outside reported hearing an "explosion" about 11.45pm.

Residents curious to know what the noise was took to Facebook, and within minutes hundreds of comments had been posted on various pages.

Neither Orana Local Area Command nor Fire and Rescue NSW Dubbo Fire Station were able to shed any light on the issue, with local emergency services workers not called to any incidents around that time.

Theories posed via local residents on social media ranged from bombs, to exploding meth labs, sonic booms, fireworks and meteorites.

Numerous residents said the bang had sparked rounds of dog barking in their respective neighbourhoods.

There were even reports the explosion "shook" some houses.