Mr Phillips said the helicopter continued to douse the major flames until about 5pm.
Meanwhile, another large scrub fire broke out on Seaforth Rd in Bowentown about 2.10pm.
Mr Phillips said it was a large fire which could be seen from State Highway 2.
Two trucks from Waihi, as well as the Athenree and Waihi Beach appliances, two water tankers and the coastguard boat were used to attack the fire from multiple angles, he said.
"Certainly, the Bowentown one, we know wind fanned that fire. It spread pretty rapidly."
Closer to Tauranga three crews from Greerton fire station and a couple of tankers were called to extinguish an 80 square metre bush fire on Adrine Lane in Ohauiti about 3.40pm.
By 6pm firefighters had all three fires under control.
Barry Low, principal rural fire officer for the Western Bay Moana Fire Authority, said the suspicious blaze at Omokoroa was large.
"We suspect it was deliberately lit. It took a lot of resources and took volunteer crews away from their Sunday afternoon with their families," he said.
Mr Low said he believed the fire at Bowentown was also deliberately lit "if not carelessly lit".
Investigations would be held into the cause of the fires, but Mr Low said there was always an increased fire risk with the arrival of summer.
"We are getting up pretty high now with a lack of rain, things are drying out pretty rapidly."
Mr Low said because of past seasons where the region experienced a lot of rain, there was now a lot of growth.
"We have a lot of fuel to burn."
He asked people to be more aware of the risk of fire and take extra care when lighting rubbish fires or disposing of cigarettes.
The Western Bay of Plenty region is under a Restricted Fire Season, meaning anyone wanting to light a fire in the open air must obtain a permit from their council.