At about 12.45am, police and CFS crews were called to a grass fire in a paddock near Whitefield Road. The fire was near a pine tree plantation, and was extinguished without any damage to the plantation.
At about midday, another fire was lit in a logging machine near Mount McIntyre.
The fire was lit after entry was forced into where the machine is located.
Limestone Coast police are treating both fires as suspicious, and anyone with information that can assist police is asked to call Crime Stoppers on 1800 333 000.
Any suspicious activity near fire-prone areas is to be reported immediately to police on 131444.