Fire crews are battling a blaze in scrub near Kaikohe in Northland and people have been evacuated from their homes.

The Fire Service was notified of the fire about 12.45 this afternoon.

It's covering an area of six hectares.

Four helicopters are battling the flames and crews from Kaikohe, Kerikeri, Kaihu, Whangarei and the Rural Fire Authority are attending.

A spokesman said there are buildings, including houses, at risk.

Crews are putting foam over the houses at risk in an effort to protect them from the flames.,

The spokesman said there are "multiple" houses in danger, and the occupants have been evacuated.

A 12-tonne digger is on its way to the scene to help with firebreaks.

The Fire Service is suggesting people who live nearby close their doors and windows to stop smoke getting inside.