A makeshift "camp fire" likely sparked a large grassfire that roared through a suburban Melbourne park and came perilously close to homes, police say.
The blaze broke out at Cheltenham Park on Wednesday and spread quickly, charring graves at a cemetery and coming close to an empty primary school.
Investigators are yet to determine whether the fast-moving blaze was the work of a fire bug or simply an accident.
Another suspicious fire erupted at a nearby Sandringham park on the same hot and windy afternoon, but police have not established a link between the two.
The Cheltenham fire reached the back fences of homes before it was contained by nearly 100 firefighters and four water-bombing aircraft.
Metropolitan Fire Brigade investigators on Thursday determined the fire was suspicious and police will investigate.
"There appears to be an area where a fire has been set, as in a camp fire," Detective Senior Constable Andrew Howell told reporters on Thursday.
"We've determined where it started but we haven't determined who started the fire and for what reason."
It was reckless to prepare any fire on such a hot and windy day, he said.
There were chaotic scenes on Wednesday afternoon as residents evacuated 40 homes, while heavy smoke billowed into the sky.
One local woman fled with her three cats tied to lengths of rope as others remained at home armed with garden hoses.
The blaze started about 2pm and was contained by 5.30pm, with residents returning to their homes about two hours later.
The Sandringham fire started in Tjilatjirrin Reserve, less than 3km from the Cheltenham fire, and spread to nearby homes, razing one and damaging another.
Despite the close proximity and timing of the two fires, police have not linked the causes.
The Cheltenham fire burned in a native conservation area and a council representative said local wildlife would have sought shelter.
"Residents living around the park may find native wildlife in their gardens," Bayside City Council Mayor Laurence Evans said.
"Injured animals can be taken to your local vet or reported to a wildlife shelter."
