The first occurred at about 9.50am when Country Fire Authority crews were called to attend a fire at the base of a tree at the corner of Salt Creek Road and Great Western Salt Creek Road.

The fire spread to nearby grassland before it was contained.

While on site at the first fire a second report of fire in the Great Western area at the corner of Churchill Crossing Road and Western Highway was made at 11.15am.

The fire was contained to grassland but strained resources with brigades from Great Western, Stawell and Ararat all having to respond.

CFA District 16 Operations Officer Ian Morley said they take very seriously any threat of fire and work closely with investigators to determine the cause.

"The community can be assured that CFA and police fire investigators are investigating the fires thoroughly and anything that points to the origin of the fires," he said.

Mr Morley said most concerning to authorities was the fact the fires were started on a dangerous fire day with high winds making the rapid spread of any fire a high possibility.

Police along with CFA are encouraging residents to be diligent and report any suspicious activity as quickly as possible. They can do so by calling Crimestoppers 1800 333 000 or triple zero (000).

In an unrelated incident CFA members were called to distinguish a small grass fire at the back of a residence in Western View Road, Great Western at 5.50pm on Tuesday night.

A four-year old child was spoken to by police along with their parents. It is believed the child was playing with a cigarette lighter or something similar at the time of the fire.

CFA and police fire investigators were also required after a fire in a farming shed at Cootes Road and Lake Lonsdale, north-west of Stawell.

The fire is believed to have started at about 1.20pm on Monday and caused an estimated $10,000 damage to property including farm machinery. Fire investigators have deemed that fire to be suspicious.