Rescue crews were still looking for victims Thursday after a tornado touched down in the outskirts of Auckland, New Zealand's largest city, killing three people and tearing through some 150 homes, local media reported.

At least seven people were hospitalized, the New Zealand Herald reported.

The tornado, driven by a powerful storm cell, tore concrete slabs from a building site and dropped them onto a truck, killing two people inside, a fire services spokesman said. A third person was killed by a falling tree.

Rescue teams were searching a school site for workers thought to be trapped beneath fallen concrete blocks in the west Auckland suburb of Hobsonville.

"I saw it coming across the river, the air went very electric and the sky went black. And then the wind started to whistle. This was like a juggernaut roaring through here," witness Suzanne McFadden told New Zealand's Newstalk ZB radio.

Hobsonville is the site of a new town center near Auckland, which is home to 1.3 million people, roughly a third of the New Zealand population.

Nigel Marple / Reuters

Rescue workers inspect the scene where two men were crushed to death in a truck when a tornado struck the outskirts of Auckland, New Zealand, on Thursday.

Photoblog: Storm slams New Zealand

Military personnel were going from door to door in the area to check if more people were trapped and authorities warned of more severe weather to come later on Thursday.

New Zealand has been hit by several natural disasters in recent years, including a magnitude 6.3 earthquake that struck the southern city of Christchurch in 2011, killing 185 people. Another tornado in Auckland last May killed one person.

The Christchurch quake caused damage worth NZ$15 billion to insurers, making it the country's costliest natural disaster. 

Reuters contributed to this report.

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