The first callout was about 2.20am at Parore, followed by Mamaranui half an hour later.
About 20 minutes later, firefighters rushed to another location at Mamaranui, then to Kaihu at 3.30am.
Mr King said scrub fires had the potential to turn into a massive blaze, similar to the one experienced at Pouto Peninsula last December that ripped through 115ha of pine forest.
The cost of fighting that fire was estimated at up to $750,000, on top of the estimated $1 million worth of pine trees lost in the blaze.
"We managed to respond on time. The danger is there is a lot of forestry in Rotu and Mamaranui and these fires, if not attended to on time, could easily get up there,'' Mr King said.
"People should watch it out there.
"A fire ban in Kaipara should be in place in the near future and anyone who sees anything suspicious should call police.''
The Kaipara fires were followed by another scrub fire at Franklin St in Opua about 4.30pm on Saturday.
Two fire appliances from Paihia managed to bring the blaze under control.
Paihia chief fire officer Shane Schrafft said the fire had the potential to be quite serious, as a chemical storage facility was located between 50 and 100 metres downhill.
He said the 30m-wide and 200m-long fire was quickly contained before it could get towards the Opua ferry area.
Mr Schrafft believed the fire was deliberately lit and said police had been notified.
He warned people against lighting fires because the Far North was extremely dry.
Last week, a major fire swept through 318ha of a Far North pine plantation, threatening homes and forcing evacuations.
The blaze is believed to have been started by workers on a government employment scheme clearing scrub for a coast-to-coast cycle trail.
A fire ban has already been declared in the Far North and the rest of Northland may follow suit with conditions tinder dry after no significant rain for months.
