An 11-year-old boy has been knifed along with a 40-year-old man at an address on Monday morning.
The pair were both found with serious injuries along with another two children aged 10 and 13 at the house in Harrogate, North Yorkshire.
Police scrambled to the property and the pair were rushed to hospital.
The boy underwent emergency surgery while the man remains in a serious condition under police guard.
Senior investigating officer DI Steve Menzies said: “I am relieved to say that following emergency surgery, the 11-year-old boy is now in a stable condition in hospital.
“The 40-year-old man remains in a serious condition and is under police guard.
"Two other children aged 10 and 13, who were also in the house at the time of the incident, are being cared for by relatives and supported by specialist police officers."
Neighbours told of hearing "awful" screams coming from the address and looking out their windows to find around a dozen police cars.
One man, who did not wish to be named, added: "It sounded awful. Enough for me to stop and look outside my window."
Another resident, who has lived in the village for more than three decades, said: "I have never known anything like this to happen before.
"It's appalling that this could happen on your doorstep. It's a tragedy."
A third told how the road was flooded with emergency crew within five minutes.
"It was a case of every available police vehicle in the area coming," he said.
"There were three ambulances, four or five unmarked police cars, three or four police vans and another three or four marked cars."
North Yorkshire Police said officers were called to the property at 8.20am and closed the road for around three hours.
Officers found the man and the 11-year-old boy inside with "serious injuries believed to be sustained by a bladed article."
The force stressed that the incident is not connected to the nearby Beckwithshaw Community Primary School.
DI Menzies added: “I can reassure the public that we are not looking for anyone else in connection with the incident and an investigation is underway to establish the full circumstances of exactly what happened this morning.
“I also want to thank ambulance staff, paramedic teams and police officers who quickly arrived at the scene and administered emergency aid to the injured males”.
NYP confirmed officers are currently at the scene and that the investigation remains ongoing.