State Highway 1 in Marlborough closed for 'several hours' following serious crash

One person is critically injured following a two-vehicle crash on State Highway One in Marlborough.

The intersection at Sheffield Street in Riverlands is blocked - with police saying it will be closed for several hours.

Police said emergency services were notified of the crash at 4.20pm on Monday.

"One person has sustained critical injuries with ambulance services on scene.

"The Serious Crash Unit has been advised.

"Motorists should avoid the highway and take alternative routes or delay travel. The area is expected to be closed for several hours as emergency services work at the scene."