A teenage boy is in critical condition and four adults, including his father, have been treated for burns after a flammable liquid was thrown into a fire pit causing an explosion at a home north of Newcastle.
The explosion occurred on a patio of the Corlette home, near Port Stephens, on Sunday afternoon.
A 16-year-old boy suffered burns to his face, arms and torso and was airlifted to Sydney's Royal North Shore Hospital is in a critical condition.
His 46-year-old father and another man, 44, received burns to their legs and torso and were also flown to the Sydney hospital.
Two others, a 44-year-old woman and 49-year-old man, suffered burns to their face and torso and were taken to Newcastle's John Hunter Hospital in a stable condition.
Police established a crime scene at the house and are investigating.