Christchurch police were called to an assault in the car park of the 24 Hour Surgery in the early hours yesterday.
A police spokesperson said the assault in the car park was reported at 3.25am on Thursday, and police were on site by 3.40am.
One person suffered injuries, but there was no further information available about their status.
Police were trying to find those involved who had left in vehicles, and inquiries were continuing as they aimed to speak to all the parties involved.
Pegasus Health, which operates the 24 Hour Surgery, said as it was a police matter all queries should be directed to police.