At about 8.55pm on Sunday (November 15) police received a report of a disturbance inside an address in the village of Linton.
Emergency services attended the property on Foxcover and found a 47-year-old woman and a 15-year-old boy with serious injuries.
The woman is in a critical condition in hospital and the teenage boy’s injuries are serious but not believed to be life-threatening, Northumbria Police said.
Enquiries are ongoing to establish exactly what has happened but police do believe that they have both been victim of an assault.
Officers are searching for a suspect who is known to the woman in question but there is not believed to be any wider risk to the public.
Detective Inspector Graeme Barr, of Northumbria Police, said: “Two people have been seriously injured and our priority now is to establish how that has happened.
“Linton is a small village with a close knit community and so there will understandably be concerns about the significant police presence in the area.
“Enquiries are ongoing to locate a named suspect who we believe is responsible for assaulting the woman and the teenage boy.
“But I want to reassure the community that this appears to be an isolated incident, inside an address, and there is no wider risk to the public.
“I would ask anyone who may have seen or heard anything unusual in the area of Foxcover last night to get in touch with police immediately.”
To report any information visit the Northumbria Police website quoting log 908 15/11/20.