Detectives from Melton Crime Investigation Unit are appealing for witnesses following a series of small grass fires in Melton South over the last 24 hours.
The three fires, all within three to four hundred metres of one another, appear to have been lit alongside a walking track parallel to the Toolern Creek.
The first fire was noticed by police yesterday afternoon when a large plume of smoke was seen across the Western Freeway near Tamar Drive about 3.30pm.
A number of fire units attended and due to strong winds, the fire quickly spread towards the road.
Police managed traffic in the area while the fire was brought under control.
A report of a second fire was received last night when police were called to assist fire authorities on the side of the Western Freeway near Melton Botanic Gardens about 7.30pm.
The small fire was quickly extinguished.
This morning emergency services were again called to the walking track following reports of another fire, about 200m north of Fraser Street, shortly before 8.30am.
This third fire was found to be in a garden bed near the dog park.
Detectives are appealing to anyone who was in the area over the last day or anyone with information about who might be involved to come forward.
It is expected an arson chemist will attend the scene tomorrow.
Anyone with information or anyone who witnessed any fire related activity in the area is urged to contact Crime Stoppers on 1800 333 000 or log onto www.crimestoppersvic.com.au.