A woman is fighting for her life in hospital after being hit by a reversing car in northern NSW.

A Subaru Forester was backing out in a carpark on Moon Street just before 9.30am on Tuesday when the vehicle collided with a brick wall and hit a 64-year-old woman.

The injured woman was treated at the scene by passers-by who ran to her aid, before paramedics arrived on scene and took over.

She was then rushed to Ballina Airport before being airlifted to the Gold Coast University Hospital in a critical condition.

The driver of the vehicle, an 83-year-old woman, was also treated at the crash scene for minor injuries before being taken to Ballina Hospital for mandatory testing.

A crime scene has been established as investigations into the circumstances surrounding the incident continue.

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