Police were called to an incident on Gamblins Rd about 11.30am, near the New World supermarket. Three houses on Wilson's Rd and the footpath has been taped off with a police scene guard in place.
A St John spokesman said the woman was taken to Christchurch Hospital.
A police spokeswoman said they are "working to locate" another person involved in the incident.
She said there was "nothing to suggest any risk to the public".
Residents have reported that a woman was allegedly stabbed, but the police said they could not confirm whether this was the case.
A person who works at a nearby business and did not want to be named, said she heard a "commotion". She said another staff member saw two men and a woman involved in an altercation.
"He saw one of the guys launch at someone," she said.
