Staff at a Napier McDonald's had to intervene in a fight outside the building yesterday.
Police were called to the Taradale McDonald's just before 5pm when two women started fighting; one had a knife.
Senior sergeant David Sutherland said the women had been part of a bigger group, but they were the only ones involved in the altercation.
He said one woman had been charged with assault and possession of an offensive weapon.
The other was shaken but generally okay.
"Although the knife was present, we don't think it had any part in the assault," Mr Sutherland said.
The women had not been patrons of the restaurant but staff had intervened.
A witness said she had been alerted to the incident when she had heard lots of "screaming and carrying on".
According to the witness, one of the women had left the scene and returned with what appeared to be a boning knife. She then left after the fight. An ambulance was called to the scene.
A St Johns spokesman said the woman was treated at the scene for minor injuries.
While the victim was being treated in the ambulance the offender returned to McDonald's for the second time, and began screaming abuse at the victim, and at police.
She was then arrested.
McDonald's would not comment as it was a police matter.