Two people are dead, two more are seriously injured and two others are in police custody following a “serious incident” in Christchurch. 

Police were called to an address on Olliviers Road, in the suburb of Phillipstown, at about 12.50am.

Detective Inspector Nicola Reeves said two people died at the scene while two others were taken to hospital with serious injuries

Two other people are in custody, and police are not seeking anyone else in connection.

Police are wanting to reassure the public that there is no risk to their safety.

"Residents should expect an increased police presence in the coming days and appreciate their co-operation as scene examinations continue,” Det Insp Reeves said. 

Det Insp Reeves is asking anyone who may have seen anything, or may have CCTV of the area, to contact 105.

Information can also be provided anonymously via Crime Stoppers.