Three people are unaccounted for following a crash in Marlborough overnight.

Emergency services were alerted to the crash at the intersection of State Highway 1 and Bush Road, Tuamarina at 1.45am.

A car with five occupants crashed off the road into the Tuamarina River.

Two of the occupants were able to get out of the car and make their way to safety.

They are reported to have suffered moderate injuries and were transported to hospital.

Three other occupants remain unaccounted for.

The Police National Dive Squad is being deployed and is expected to arrive in Marlborough around midday.

One lane of State Highway 1 is closed and stop/go traffic management is in place.

Full closures of State Highway 1 may be required at some points during the day.

Motorists are asked to expect delays and allow extra time for travel.

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