Police were guarding the scenes of two suspicious fires in the Auckland region overnight Wednesday.
The first at about 9.30pm, destroyed the Scout Hall in the suburb of Point England and the second, at about 2.30am, damaged the town hall in Waiuku.
Fire service spokesperson Jarron Phillips says at the scout hall, much of the firefighters' work was stopping the large blaze spreading to neighbouring properties.
Mr Phillips says the Waiuku town hall was probably saved because a fire alarm was activated early.
There was also a kiln fire at the Carter Holt Harvey mill in Kinleith but it is not suspicious and was quickly brought under control.