Children flee house fire in Sydney

Six children including a baby have fled from a burning house and a man suffered an electric shock from fallen powerlines after a blaze broke out in Sydney's southwest overnight.

Emergency services were called to the house in Cabramatta West at about 12.40am on Sunday to find the property well alight.

Six children, aged between one and 14, had already fled the blaze while a 22-year-old man, who was reportedly the father of some of the children, suffered an electric shock after power lines fell on the front fence of the home.

He's been taken to Liverpool Hospital in a stable condition, while three of the children were treated for smoke inhalation before being taken to hospital as a precaution.

Fire & Rescue NSW superintendent Paul Johnson says it's believed a heater sparked the blaze.