At least one person is critically injured following a serious crash on State Highway 1 south of Waiouru.
The crash, involving a truck and a vehicle, was reported about 11am on Tuesday. The truck rolled, police said, blocking SH1 between Hassett Drive and Waiaruhe Road.
"The driver suffered minor injuries and was taken to hospital for treatment."
Police said the serious crash unit and traffic management had been advised, and motorists should expect delays up to half-an-hour as the truck was salvaged.
It was the third serious crash on the North Island's state highways on Tuesday morning, after a bus and truck crash on SH1 near Marton and a container truck that rolled on SH2 at Putorino, south of Wairoa.