Melbourne fires: Suspicious fires take hold of three unoccupied homes across Melbourne

An investigation is underway into three separate suspicious fires at unoccupied homes across Melbourne .

Emergency services were called to Craigieburn, Glen Waverley and Noble Park as homes went up in flames before 5am today.

In Craigieburn, the home burnt to the ground with neighbours describing it as "intense" and "terrifying".

Fire Rescue Victoria's Paul Buck said authorities have suspicions that something sinister must have sparked the blaze.

"The house was unoccupied, and there doesn't appear to be much furniture in there," he said.

"So for a fire to be burning as hard as it was at this point suggests there may have been some other interaction with the building"

Neighbours told 9News the home was known to be used by squatters. 

Around the same time, a car was seen