Whale stranding in New Zealand sparks rescue mission

"Around 40 whales were sighted and sadly 25 have stranded," a spokesman for the conservation group Project Jonah said.

Project Jonah general manager Darren Grover told reporters they were trying to keep the whales cool and healthy and would try to refloat them on the evening high tide.

Pilot whales, which can grow to more than six metres (20 feet) long, are prolific stranders and more 376 died in a mass stranding in Australia last month.

That was Australia's largest-ever mass stranding, with around 470 pilot whales stuck in a remote harbour on Tasmania's rugged western seaboard, sparking a major effort to save the animals.