A show home and a classroom were set alight in four "suspicious" fires over four hours south of Auckland last night.
Fire crews and police were called to the first fire at a Portacom on Hingaia Rd in Karaka at about 7.30pm.
A police spokeswoman said about 10pm they received reports a show home on McPherson Rd in Drury was extensively damaged by fire.
Emergency services were also later called to a classroom fire at Puni School at 10.37pm, and on Blake Rd in Puni growers crates were on fire at 11.40pm.
A Fire and Emergency NZ spokesman said the Puni School fire was contained to one classroom in a block of three.
Fire investigators would be working with police to determine the causes of the fires.
Police request anybody who was in the areas at the time and saw anything out of the ordinary contact Counties Manukau Police on (09) 261 1300 or Crimestoppers anonymously on 0800 555 111.