A large blaze at a pine plantation at Kentbruck in Victoria's far south-west has jumped a containment line.
The fire has burned through nearly 3,000 hectares of plantation and national park between Nelson and Portland since Friday.
Crews are relying heavily on water-bombing aircraft because ground equipment cannot be used in the boggy terrain.
But the Country Fire Authority says it is still not posing a threat to lives or property.
Nearby, a watch and act warning has been issued for the communities of Drik Drik, Greenwald and Winnap after a small bushfire broke out north of the Kentbruck bushfire.
The fire is expected to impact the towns any time in coming hours and residents are being advised to follow their bushfire survival plans.
The Winnap-Nelson Road has been closed.
Fire crews have controlled a grass fire near Little River, south-west of Melbourne, and another blaze south-east of Echuca.
Meanwhile, lightning sparked up to five bushfires around the Corryong area, east of Albury-Wodonga in the state's north-east.
They have all been contained but firefighters are bracing for more hot and dry conditions across the region again today.
Elsewhere, a woman has been charged with deliberately starting a bushfire in Melbourne's north.
Firefighters were called to a grass fire on an embankment at the Gardiner Creek Trail in Ashwood just before 10pm (AEDT) last night.
The 18-year-old was arrested at the scene.
She has been ordered to appear in court in April on charges of intentionally causing a bushfire and reckless conduct endangering life.