About 3.30am (Wednesday June 26), officers from Hunter Valley Police District were called to Brittliffe Close after reports a house was well alight.

Officers from Fire and Rescue NSW attended and are in the process of extinguishing the blaze.

A 31-year-old woman and an eight-year-old girl were treated by NSW Ambulance paramedics at the scene for smoke inhalation, before being taken to Singleton Hospital.

They are now being treated at John Hunter Hospital and their condition is reported as being stable with the woman being treated for burns to her back and forehead..

Two girls, twins aged five-years, were taken to Singleton Hospital, where they were pronounced deceased.

Another boy, aged 11-year, was located deceased inside the home.

At a press conference held in Tulloch Close this morning Hunter Valley Police District Commander Superintendent Chad Gillies praised the heroic efforts of neighbours saying " four residents assisted in removing the mother and her daughter from the house safely."

When it is deemed safe to do so, police and fire investigators will examine the home to identify where and how the fire started.

Police will prepare a report for the Coroner outlining the full circumstances surrounding the incident.

A GoFundMe has been established to assist the family at this tragic time.

Our community is mourning the loss of three children, including an 11-year-old boy and two five-year-old girls, in a tragedy that has changed the lives of many in our community forever.

Singleton Mayor Sue Moore has released statement:

Our thoughts and prayers are also with the 31-year-old woman and eight-year-old girl who are being treated in hospital as a result of the house fire this morning.

The situation confronting those who responded to the fire on Brittliffe Close in the early hours of this morning is hard for anyone to imagine, and I pay tribute to the heroism of the neighbours who were on the scene in the first instance and the emergency services who responded.

We are proud of our tight-knit community in Singleton, and a tragedy like this, particularly with children involved, will touch everyone in some way. We will all band together to offer ongoing support to neighbours, schools and everyone in the wider community who have been affected.

Again, I wish to highlight the bravery of the neighbours and emergency service workers who attended the scene, and support the efforts of the NSW Police, NSW Fire & Rescue and NSW Ambulance to provide the ongoing assistance they will no doubt need in the aftermath of this event.

To everyone who has been touched by this tragedy, I offer our community's deepest sympathies.

I also sincerely thank Member for Upper Hunter Michael Johnsen MP and my colleagues from other councils who have reached out to offer their thoughts and prayers at this difficult time.