TWO large bushfires burned through the pine forest near Yarrabilba over the weekend.
The first blaze started about 12.40pm near Waterford-Tamborine Road on Saturday. The fire spanned almost 600 acres, with firefighters battling the flames well into the night.
A second blaze burned near Plunkett Road on Sunday, spanning about 200 acres.
As of Monday morning, fire was still burning within containment lines and firefighters had left the scene.
Crews from the Jimboomba, Tamborine, Logan Village, Birnam, Chambers Flat and Greenbank rural fire brigades fought the blazes over the weekend.
Logan Village Rural Fire Brigade first officer Simone Hague said the cause of the fires were unknown, but they were being treated as suspicious.
Four bushfires have burned in the pine forest in the past week. It posed no threat to property, but produced large volumes of smoke.
Residents in the area were advised to keep doors and windows shut and keep medication on hand for those with breathing difficulties.
Meanwhile rural fire brigades, including a crew from Greenbank, helped fight a bushfire south of Ripley over the weekend.
Water-bombing helicopters were brought in to fight the fire, which spanned more than 180 hectares.
Smoke from the blaze could be seen from Greenbank while the fire burned.