We have received reports of two explosions and a large fire at Crown Farm Industrial Estate, Crown Farm Way, Mansfield Woodhouse.
An eyewitness, who lives on the Avenues said: "There was a noise that sounded like a shotgun, and as I was telling my friend what I'd heard, there was another loud explosion.
"I could see flames from my garden and there's been no end of emergency services racing to the scene.
"I hope no one was hurt."
Paul Tebbott, a resident aged 62, said: "I drove past at around 4.30 and saw nothing and it was normal but my neighbour called at around 4.45 and said he could see it from his house in forest town.
"I hope everyone in there is okay"
A reporter is at the scene, and we will bring you more news on this as we receive it.