Police are investigating after two people were left in a critical condition after an explosion overnight.
Police say they were called to a Forest Street, Oak Flats address at around 7 o'clock after a blast that shook nearby homes and was heard for several kilometres.
Inquiries revealed a couple had opened the door of a shipping container at the back of the property when the explosion occurred.
It's believed an oxyacetylene canister had been leaking and ignited when the gas came into contact with a lit cigarette.
The man and woman have suffered serious burns and have been flown to Royal North Shore Hospital for treatment.
A crime scene has been established and police will be back at the scene today.
image:Highway Patrol Images [CC BY (https://creativecommons.org/licenses/by/2.0)]