Killer whales swim frighteningly close to NZ children

Two killer whales came within a few metres of children swimming in a bay on New Zealand's North Island on Saturday, with the frightening experience filmed by an onlooker.

The unnamed cameraman was standing above Enclosure Bay on Waiheke Island when he saw two large dorsal fins break the surface of the water.

He shouted at swimmers to get out of the water after mistaking the orcas for sharks, but two children were still in the water as the whales approached.

"Everyone got out of the water, however, there were two children in the middle of the bay who must not have heard the call to get out," the cameraman said.

"By the time they realised what was going on it was too late, it appeared the whales heard the children calling for help and headed directly for them."

The children screamed and started to swim frantically for dry land as the orcas approached.

"Stay still!" onlookers shouted at the kids.

"Chill!"

When the children started to tread water, the killer whales swam past, coming very close to the kids without touching them.

The killer whales were only metres away when the onlookers began reflecting on the moment.

"That's cool. That's a lifetime experience for you," one said.

Despite their fearsome name, there have been no instances of killer whales making a fatal attack on humans in the wild.

They do have a documented history of eating much larger prey, including great white sharks, minke and grey whales, sting rays and even swimming deer and moose.