9.04pm: State Highway 25 between Moewai Road and Kaimarama Road is now reopen following a serious crash earlier today, according to Waka Kotahi.

The road had been closed since about 1.15pm.

Earlier 1.19pm: State Highway 25 between Moewai Road and Kaimarama Road is closed following a serious crash.

Emergency services are at the scene.

"Police were called shortly before midday," says a police spokesperson.

"Initial reports suggest two people have been seriously injured.

"The road is closed and there is no available diversion.

"Please consider delaying travel, or expect delays."