At least one bach has reportedly been destroyed and other properties are being evacuated after fire broke out on Kawau Island tonight.
A Fire Service spokesman said numerous calls started coming in from 7.30pm about the blaze near Vivian Bay, to the island's north.
Two helicopters had arrived from mainland to help a small crew of rural firefighters. Further crews were being deployed on boats from Sandspit.
A Kawau Island resident, who asked not to be named, said at least one bach had already been destroyed and Vivian Bay residents were being told to evacuate.
"I was pretty impressed with the response ... the helicopter was probably there within 20 minutes, half an hour after the fire started. It's pretty amazing."
He said there had been a fair bit of rain on the island up until Christmas so it was not tinder dry, but there was still a fire ban in place.
Fortunately, the wind was blowing towards the sea and not inland.
There is limited fire-fighting capacity on the island, where there are about 60 permanent residents. The population swells over summer when bach owners arrive.
There are about 20 houses in the vicinity of the fire. The terrain is quite steep and is currently covered in dry vegetation.