Fire crews put out four suspicious fires on the Port Hills in Christchurch overnight, with one eyewitness saying a fire he spotted could have been so much worse.
Between midnight and 2am, Fire and Emergency put out two fires in Sumner, one in Sugarloaf, and one near Governors Bay.
A Fenz spokesperson says the blazes are being treated as suspicious due to witnesses seeing people leaving the scene.
One eyewitness has told RNZ he is hugely relieved he managed to sound the alarm just in time, and said things could have been dire had he not been there.
Caleb Alexander saw a spark fly past the radio tower at Sugarloaf.
"We didn't hear anything, just saw a red spot float down and when it did it hit the grass and it took 30 seconds to a minute to ignite.
"With the recent Port Hills fires a few years back ... it wasn't the best feeling knowing how crazy it could have got," he said.
Alexander said they warned five other groups who were also on the hills about the blaze.
The fire at Sumner was two square metres in size and the other three ranged from 50 to 100 square metres.
A fire investigation is ongoing.
The city has been experiencing strong norwesters in the last two days.