An ambulance spokeswoman said they had attended the incident and transported a patient with minor injuries to Rotorua Hospital.
A Rotorua Daily Post journalist at the scene said a man with a bandage on his neck walked to an ambulance parked outside.
The journalist said some customers had told her they didn't know what had happened but the store was closed in the afternoon while police conducted an investigation.
She said police officers could be seen inside the store. There were three police cars parked outside the store and one ambulance.