POLICE launched investigations yesterday into the circumstances surrounding two backyard burn-offs at Woodburn and Clunes during Wednesday's total fire ban.
Police believe another blaze in Goonellabah was started by a discarded cigarette.
While RFS officers were able to put out the fires before they caused any damage, Detective Inspector Greg Moore of Richmond Local Area Command said police had a zero tolerance policy for such behaviour.
"Obviously the total fire ban extends to backyard burn-offs... penalties start at $1100 for basic infringements, and depending on the circumstances and recklessness involved can extend to far more serious fines and possible imprisonment," Det Insp Moore said.
"You'd have to be fairly ignorant to not be aware of what was going on with respect to the state's fire situation," RFS Northern Rivers Superintendent Boyd Townsend said.
Total fire bans are expected to continue over the weekend, with more extreme temperatures and strong north-west winds returning.
The RFS has already suspended all fire permits until further notice due to the excessively dry weather.
The fire threat has been compounded by more than 100 dry lightning strikes on Wednesday night from Woodburn through the Richmond Range to the Queensland border.
A fixed wing aircraft was deployed over the affected areas yesterday to keep watch for smoke.
"We're trying to manage the ignitions across the landscape as ground moisture levels are incredibly low," Supt Townsend said.
The RFS is also conducting round-the-clock monitoring of a five hectare peat fire about 1km east of Woodburn, burning since December 17.
RFS officers are concerned embers could drift into woodland.