Local media are being instructed to use the standard emergency warning signal to alert those in the vicinity, a measure reserved for the most serious and life-threatening scenarios.
As of 5.11pm on Saturday, the fire was burning in the Lake Lenthall and Wongi State Forest area near Duckinwilla and was travelling southwest towards Doongul Creek.
"If you left the area, stay where you are," Queensland Fire and Emergency Service said in the alert.
"It is not safe to return."
The emergency area was between Top End Mines Road, Top Road, Lenthall Dam Road and Lake Lenthall including Kellogum Foresty Road.
Those still in the area were told to follow their bushfire plans and be prepared to leave in case the situation changes.
No properties were at risk from the fire with conditions having eased, but the QFES warned it could quickly worsen.
People have been urged to remain vigilant as smoke in the area could make it hard for some people to breathe and see while driving.
Firefighting aircraft were assisting ground crews attempting to bring the blaze under control.
9°C