A cloud of smoke hovering over the Kooralbyn Valley was caused by a flare up, say firefighters.
Rural Fire Service logistics officer Gary Fordham said the black smoke was the result of embers travelling on the wind to ignite a patch of previously untouched ground in the middle of bushfire affected scrub near Kooralbyn.
"The fire is still within containment lines and we are happy with how it is behaving," Mr Fordham said.
"We will have crews monitoring the fire until midnight and we will be back at 8am tomorrow. Saturday and Sunday we will have firefighters out there from 8am till midnight."
KOORALBYN residents concerned about the increase of smoke in the valley can rest assured that the bushfire burning since Sunday is still well within containment lines.
A spokeswoman for Queensland Fire and Emergency Services said the fire is now tracking uphill but the extra smoke is from backburning.
Rural Fire Service incident controller Kay Healing said more crews had been called in this afternoon to deepen containment lines.
"We have aircraft to rehydrate the gel lines set down yesterday in the south-west corner and we will be monitoring the fire closely in the next few days," she said.
"We will be keeping an eye on trees close to the fire ridge to make sure nothing falls across the lines."
Ms Healing said although deteriorating weather conditions were had been predicted into the weekend, firefighters were not concerned about embers igniting secondary fires, as happened during last summer's devastating bushfires.
"We don't have the same weather, you need convection type activity and this is not coming in the next seven days," she said.
"We are not at risk of embers picking up and traveling kilometres away."