A man has been fatally shot by police after a woman was attacked in a terrifying home invasion on the NSW mid-north coast on Friday.

Police were called to a home in Tuncurry, about 300 kilometres north of Sydney, about 6.40am after reports a man armed with a chainsaw and knife had broken in.

Before they could get to the Heath Avenue home, they were told the 28-year-old woman had been stabbed and the man had fled in a white four-wheel drive.

NSW Police Assistant Commissioner David Waddell said the woman was “stabbed a number of times”. He said early investigations indicated she and the dead man were “in a de facto relationship”, and would not rule out domestic violence.

“It’s too early to say what the exact motives are,” he said.

The woman was treated by paramedics before being flown to the John Hunter Hospital in Newcastle in a serious but stable condition.

Police said officers saw the 4WD nearby soon after. They began a pursuit, during which the vehicle drove through a sportsground before crashing on the Forster Bridge.

“Police attended the bridge, locating the crashed 4WD and were told the man had carjacked another vehicle, which subsequently rammed a police vehicle. An officer sustained minor injuries,” they said.

There was a second pursuit, which went into nearby Rainbow Flat. Police allege the man drove onto a property, entered a home while still armed with a knife, and tried to steal another vehicle.

“The armed man exited the home moments later and confronted police. Officers deployed a Taser in efforts to detain the man; however, he was able to run to a neighbouring property,” NSW Police said.

“A Taser was deployed multiple times before the armed man ran towards an officer who discharged his firearm, shooting the man.”

Police gave first aid until paramedics arrived. However, the man  died at the scene.

He has not been formally identified but is believed to have been aged 41. He was previously known to police.

Waddell said the incident was “quite threatening”.

“He’s engaged with the police with a knife and kind of threatened other people,” he said.

“This is a very quite threatening incident. There are multiple lives at risk here.”

He said there was no further risk to the public.

A critical incident team from State Crime Command’s Homicide Squad will lead the investigation into the circumstances surrounding the incident.

The investigation will be reviewed by the Professional Standards Command and oversighted by the Law Enforcement Conduct Commission.