One person died and three others were injured in a two-vehicle crash on the road to the Lyttelton Tunnel in Christchurch this evening.
Police earlier reported only one vehicle was involved and they now say detectives are investigating the crash.
Three men and a woman were in the first vehicle when it collided with a bridge on Tunnel Road about 5.30pm, says Canterbury Metro Commander Superintendent Lane Todd.
The woman died at the scene and the men sustained minor to moderate injuries.
The second vehicle collided with the first before also hitting the bridge.
Its driver, the sole occupant, was taken to hospital with minor injuries.
Tunnel Road will remain blocked for a number of hours, Mr Todd said in a statement released shortly before 7pm.
The Serious Crash Unit and CIB are investigating, he said. Police are advising motorists to avoid the area if possible as Tunnel Road is not accessible via Port Hills Road or Ferry Road.
Police will release further detail tomorrow, Mr Todd said.