UPDATED: 9:19pm: Six people were taken to hospital after a crash involving two cars and a stock truck.
Two had serious injuries and the other four had moderate injuries.
EARLIER: Three people are believed to be trapped after a crash on State Highway 29 near the Maungatapu bridge.
Police Northern Communications Centre shift commander Jason Greenhalgh said "it appears that we have two vehicles involved and two people are trapped in one car and one is trapped in the other. There are multiple injuries and we've got traffic diversions at the roundabouts".
State Highway 29 was closed from the Maungatapu bridge to the Maungatapu roundabout.
A reporter at the scene said the crash was on the Welcome Bay side of the bridge. Three ambulances, two fire trucks and multiple police cars were at the scene.