A man has suffered serious head injuries after a stabbing at an Invercargill house today, police say.

Senior Sergeant Dave Raynes, of Invercargill police, said the man had head wounds, believed to be from a knife.

Police had yet to locate the person responsible, he said.

Detective Sergeant Mike Bowman was investigating and a forensic team was at the Earn St house.

Police were also investigating a serious assault in the city at about midnight this morning.

One female and two males were injured with a variety of weapons in Nelson St, Raynes said.

One of the injured was taken to Southland Hospital with serious facial injuries.

A 50-year-old man was at the station, helping police with their investigation, he said.

- © Fairfax NZ News