State Highway 1 in Marlborough reopens 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 was blocked earlier - with police saying it will be closed for several hours.

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

The Serious Crash unit was notified.

Just before 8pm, police said the intersection was clear.

"Police thank motorists for their patience."