Six homes destroyed, bushfire tipped to burn for weeks

A bushfire between Raglan and Mount Cole, west of Ballarat, has destroyed at least six homes. (David Crosling/AAP PHOTOS)

Six homes have been destroyed as a bushfire continues burning in western Victoria.

More than 500 firefighters are tackling the blaze west of Ballarat that has torn through about 17,000 hectares.

The fire, between Raglan and Mount Cole, was still not under control on Sunday, with authorities warning it could still burn for weeks.

A watch and act warning was in place for towns including Amphitheatre, Elmhurst and Raglan.

Residents in this area were warned it is still not safe to return to their homes.

An advice warning was in place for areas around Ballarat, and a number of roads remain closed in the area. 

Temperatures are set to spike in the coming week, with Wednesday of most concern to firefighters.

Premier Jacinta Allan said around 700 people were out on the fire ground to battle the blaze. (David Crosling/AAP PHOTOS)

The Bureau of Meteorology said the mercury is set to soar above 40C and the hot weather will be joined by strong, gusty winds. 

"All of the elements that do lead to dangerous fire conditions are starting to rear up again on Wednesday," senior meteorologist Angus Hines said.

"We've got many areas of western Victoria at extreme fire danger for Wednesday ... there's a possibility that even more areas could see that extreme fire danger rating or even a chance they could be upgraded to catastrophic fire danger."

Emergency Services Minister Jaclyn Symes said the Country Fire Authority has expressed "grave concerns" about conditions on Wednesday, and warned residents to make preparations.

"Don't leave it to make decisions until it's too late," she said.

So far, 228 impact assessments have been completed, and Ms Symes said "support measures" would be announced for affected communities.

The blaze has swept through about 17,000 hectares of land and could burn for weeks to come. (David Crosling/AAP PHOTOS)

Ms Symes said the bushfires could continue to burn for some time, and crews will be rotated to prevent fatigue. 

"Even without Wednesday's weather, that fire will not be put out until about three weeks," she said.

"We know that our first responders are going to be out in the field for many days and we want to make sure that we're looking after their health and wellbeing." 

Relief centres are open at Ararat and Maryborough for those who've had to evacuate.