New Zealand: Auckland declares flood emergency as student goes missing in cave

New Zealand's biggest city Auckland has declared a state of emergency after torrential rain caused widespread flooding.

Rescuers are also searching for a high school student missing in a flooded cave north of the city.

Heavy rainfall on Tuesday filled basements, stranded cars, toppled trees and disrupted rail services.

The torrential rains are expected to last until Wednesday evening local time.

A state of emergency was declared as a precaution and disaster response services have been mobilised, Auckland Deputy Mayor Desley Simpson told reporters.

She described the flooding as an "evolving emergency situation".

Rescue teams were dispatched to Abbey Caves about 2.5 hours drive north of Auckland in search of a missing student, whose classmates made it out of the flood-prone cave safely.

"Our thoughts are with the whanau (family) of the missing child, as well as all those involved in the group outing and the school," police Superintendent Tony Hill said.

From January to April, the Auckland region received 90% of its average total annual rainfall, the New Zealand Meteorological Service's Georgina Griffiths said, with some areas receiving up to 35mm (1.3in) of rain in just one hour.

"The region is very saturated after a very rough five months. We're pretty soggy," she told reporters.

Authorities advised people to postpone unnecessary travel and avoid driving on flooded streets.

Images on local media showed people rushing out of office buildings to go home early, causing traffic jams in some parts of the city.