"There’s no other way you can describe it," said Brett McFadden, acting region commander of the NSW Police north-west region metropolitan command. "It’s an absolutely horrible incident to unfold ... you’ve really got a family struggling to come to terms with it." A woman in her 30s, believed to be the children's mother, arrived shortly after police. She was treated by paramedics at the scene for severe shock, and is now with friends. Fairfax Media understands police are searching for a man believed to be the father of the children.

On Thursday evening, acting Commander McFadden confirmed a key person of interest was still at large. "But we believe this incident to be a targeted incident, so there are no risks to the community at this time," he said. He would not confirm who the person of interest was, but police sources have confirmed to Fairfax Media that he is a male in his 50s. Police Acting Assistant Commissioner Brett McFadden (left) and Inspector Kevin McSweeney from NSW Ambulance. Credit:James Brickwood "There are a number of witnesses that may be able to assist us and we are working with them closely this evening," acting Commander McFadden said.

'Nothing we could do to help them' NSW Ambulance Inspector Kevin McSweeney was one of the first paramedics to arrive at the house on Hull Road and said the call-out presented "an extremely distressing and stressful situation. "We found two teenagers deceased in their bedroom and unfortunately at that time there was nothing could do to help them. However, we have been assessing and treating a female in her 30s [for shock] at the present time." Mr McSweeney said the woman had left the home and was now in the care of friends. A NSW Ambulance chaplain attended the scene to support paramedics.

Scene of shooting where two children have been killed. Credit:James Brickwood More than four hours after police arrived at the home, Hull Road remained cordoned off by police cars. Earlier, a helicopter could be heard overhead. Police were still doorknocking residents along Hull Road at 9.45pm. Acting Commander McFadden said the focus of investigators was locating the person of interest, while the home would be subject to an extensive examination. "The circumstances of what happened inside the premises is subject to a forensic investigation and that includes the victims themselves."

Officers from Ryde Police Area Command are working with the homicide squad to establish the circumstances of the children's deaths. John Howard has lived on Hull Road since 1964 and said the tragedy was " absolutely shocking". "It’s made me a bit shakey," he said. "I did hear a loud noise and when I think back it could have been around 5 or a bit later."

Mr Howard said he did not know the family involved but said they were "younger people ... A lot of young people have been moving into the area." Another neighbour described the shooting as "very shocking" and said they did not feel comfortable going outside until the suspect was apprehended. "Stuff like this doesn’t happen around here," the neighbour, who asked not to be named, said. "Before, the area seemed peaceful and pleasant. Now it just seems dark and, to be honest, a bit scary." with Josh Dye