Investigations into the cause of the fire which broke out on Mauao late last week have found the blaze was deliberate.
Pumicelands Rural Fire Authority has been working to determine the cause of the fire that ignited about 12am on Thursday in Mount Maunganui - burning between 800-900 sq m on the northeast side of the mountain.
Pumicelands zone manager Alan Pearce said the results of their investigation pointed strongly towards a deliberate attempt to cause a fire by throwing fireworks from the top of Mauao.
"We believe they have tossed fireworks over the edge of the mountain, starting a fire in the northeast area above the Waikorire Track, which remains closed.
"This started the scrub fire which then spread across and up to the top track."
Tauranga City Council have just this afternoon reopened the Waikorire Track, after geologists completed rock stability assessment and hazard mitigation of the fire ground.
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Mr Pearce said it was hard to understand why anyone would commit such an act.
"It's incredibly disappointing and I encourage anyone with further information to come forward. This wasn't accidental."
Investigations are continuing with police to identify those responsible, he said.
"A number of exhibits are yet to be forensically examined. Once examined, we believe these will be helpful in providing identification evidence."
Anyone with information can contact Tauranga Police on 07 577 4300.