New Zealand police superintendent Tony Hill said one student was missing at the Abbey Caves, near Whangarei, after a group of 15 high school students and two adults got into difficulty.

The remaining 16 are accounted for.

Police rescue teams suspended operations at 5pm after an all-day search of the area, which was hit by heavy rain throughout the day.

A cordon will remain around the site until the search resumes at first light.

“Our thoughts are with the friends and family of the unaccounted for student,” said Hill in a statement.

“The school is also being supported by the ministry of education’s traumatic incident team.”

Rainfall is wreaking havoc across the region, with a number of main roads closed.

In the country’s largest city Auckland, schools have been evacuated and roads and parks are flooded.

A local state of emergency has been declared and two civil defence shelters have opened.

Heavy rain and thunderstorms are forecast to drench the region into the evening and potentially through to midnight as the storm system works its way southeast.

Auckland experienced serious flooding in January that killed four people, and then in February, Cyclone Gabrielle caused widespread damage across much of the North Island and left at least 11 people dead.

New Zealand treasury estimates the cost of those weather events at between NZ$9 billion and NZ$14.5 billion.