A man is "fighting for his life" in hospital after being stabbed during a break-in at a family home, police have said.
Officers were called to the scene at Halam Hill in Halam, near Southwell, at about 04:10 GMT on Thursday.
Nottinghamshire Police said a 65-year-old found inside had suffered two "puncture wounds" to his abdomen and chest and was taken to Queen's Medical Centre in Nottingham for surgery.
A 55-year-old man has been arrested.
Police said the injured man had gone to investigate the sound of breaking glass before being stabbed by the suspect, who then fled the scene.
Det Insp Gayle Hart said the man's family was upstairs at the time of the break-in and has been left "extremely shocked and upset by the ordeal".
"This is a horrific incident which has left a man fighting for his life," she said.
"The victim is in the intensive care unit and is currently in a serious but stable condition.
"Detectives are working hard to establish the circumstances and progress the investigation as quickly as possible."