A man is in a stable condition in Middlemore Hospital's National Burns Centre after falling into a bonfire in Pukekohe during Guy Fawkes celebrations last night.

Emergency services were called about 8.30pm, where a bonfire was burning in the middle of a paddock.

Firefighters attended 12 small fires in Auckland and the Far North.

In other parts of the country, fire crews were kept busy with minor Guy Fawkes-related callouts.

The Central region fire service said it was a busy night responding to reports of fires on beaches and in backyards, but none were serious.

Southern firefighters had a busy Guy Fawkes night with 27 fireworks-related callouts, mostly in Canterbury. Southern fire communications shift manager Brent Dunn said all fires were minor and were able to be treated quickly.

The East Coast of the North Island was also kept busy with a number of beach and backyard fires in Gisborne and Hawke's Bay.

Meanwhile, WorkSafe is continuing to investigate how six people were injured at a public fireworks event in central Christchurch on Friday.