Christchurch police have charged one man with assault following a street brawl that saw four men sent to hospital.
Up to eight people were involved in the brawl on Simeon Street, in the suburb of Spreydon on Tuesday night.
"At this stage we do not know specifically what has triggered the fight," said Detective Senior Sergeant Greg Murton.
However, it may have happened after a group arrived at the house.
"There are indications of some history of contact between the two groups of people."
Weapons were involved, but police are not saying what they were.
The charged man, in his 30s, was one of two men treated at Christchurch hospital and then discharged.
Two other men remain in hospital on Wednesday.
The charged man has appeared in court and was remanded on bail to reappear on August 7.
A scene examination is expected to continue for one or two days, with about a dozen police working on the investigation, Det Sen Sgt Murton said.
One resident told Fairfax he could hear yelling and fighting from inside a house.
"It sounded like there was a dog fight," he said.
When he went outside he saw about eight people - "there could have been more" - in the middle of the road.