A bloody street brawl in Christchurch last night has left a man fighting for his life in hospital.
A dozen police officers are investigating the fight between a group of young men in their 20s, which broke out in Simeon Street, Spreydon, about 7.50pm.
Police say weapons were used in the clash which resulted in four people being taken to hospital.
One man is in a critical condition, while another is deemed serious, and both require surgery for their injuries.
Two others have since been discharged from hospital and will be questioned by detectives today.
Witnesses described hearing yelling and seeing fighting from inside a house and later a "pool of blood'' was seen on the road.
A section of the road was cordoned off after the fight.
This morning, a scene examination is ongoing at the street, as well as in a house and cars involved in dropping the wounded men off at Christchurch Hospital Emergency Department.
Detective Senior Sergeant Greg Murton said the people believed to be involved in the incident had left the area before police arrived.
"Our focus today will be on establishing what has happened,'' he said.
"We spoke to people in the area last night and this morning we will be continuing an area canvass, talking to residents in the vicinity of the address.
"We spoke briefly last night to the four men in Christchurch hospital, but we have yet to formally interview them. We will interview two of the people hospitalised today.''
He confirmed that weapons were involved in the fight but would not reveal exactly what was used.
The nature of the injuries would not be released either, Mr Murton said.
He said the scene examination could take two days to complete.
Around a dozen police staff are working on the investigation today, trying to work out the extent of the brawl and how it started.
Mr Murton said it was unclear how many people were involved, or if the brawl occurred only in the street or inside a house as well.
- APNZBy Kurt Bayer @KurtBayerAPNZ Email Kurt