Bushfire's smoke so dense it set off home smoke alarms

ABOUT 120 square kilometres of bushland in the Imbil State Forest and Conondale National Park has been destroyed huge bushfire that firefighters say may continue burning for weeks.

The area destroyed so far by the bushfire is roughly equivalent to all the land between Mooloolaba and Caloundra, out to the Bruce Highway.

Despite the size of the blaze, Queensland Fire and Emergency Services personnel, along with officers from Queensland Parks and Wildlife Services and HQ Plantations, have managed to keep it from threatening any homes.

Residents at Imbil say at times this week smoke from the fire has been dense enough in the township to set off smoke alarms in people's houses.

Earlier in the week firefighters had to use aircraft to dump water on the blaze as they fought to bring it within containment lines.

However, the efforts of firefighters combined with favourable weather conditions in recent days means the blaze is now firmly behind containment lines.

Queensland Fire and Emergency Services says the remote terrain the fire is burning in makes it difficult to fight directly.

At present, a total 15 firefighting crews from the three agencies remain on the scene, patrolling the containment lines to make sure the fire doesn't break out again.

A spokeswoman for the QFES said the crews were expected to remain in place until at least the next five days.

Fire investigators are still working to determine the cause of the blaze.

Although no homes were threatened by the fire, the QFES says residents may still be affected by smoke from the fire. It is advising them to keep windows and doors closed and to keep medications close by if suffering from a respiratory condition.

Motorists should drive with caution and to conditions.