A Glandore woman has been arrested for allegedly slashing at the throat of another woman at South Plympton.
The 24-year-old victim from Flinders Park was taken to hospital and treated for a minor wound to her neck.
The woman had been sitting with three men at the front of a house in Pleasant Avenue just before midnight when an altercation began with a woman who was walking by.
Police say the passer-by pulled out a knife from her handbag and slashed at the throat of the victim.
Police are yet to lay charges.