Sydney, Jul 12 (IANS): Authorities in the Australian state of Victoria said on Friday that there is no indication of the massive factory fire in Melbourne being suspicious.

Fire Rescue Victoria (FRV) confirmed in a statement that 20 firefighters and five appliances are still working on the scene after a significant chemical explosion caused a huge fire in Derrimut on Wednesday.

"The incident remains under control but there are still hotspots in inaccessible areas due to structural integrity and site contamination concerns. Over the next 24 hours, FRV crews will continue to suppress hotspots and take the heat out of locations that are still burning," said the authority.

FRV investigators are working with WorkSafe and Victoria Police to investigate the incident, while there is currently no indication the fire was suspicious, according to the fire authority, reported Xinhua news agency.

FRV Deputy Commissioner Josh Fischer said that authorities would remain at the scene for days, if not weeks.

"This is a complex and dangerous environment, there are a lot of hazards associated with this incident so we're taking extreme caution and care as we manage those risks for our firefighters from the time of the incident and into the future," Fischer said.

The incident unfolded at around 11:20 a.m. local time on Wednesday. Emergency services rushed to a factory on Swann Drive in Derrimut, which contained a range of chemicals including kerosene, fuel, methylated spirits, and ethanol.

Following a large explosion, flames burst out at the site, with toxic smoke billowing towards the east across Derrimut.

As of Friday, Environment Protection Authority (EPA) Victoria updated that preventing further environmental damage to waterways continues to be a major focus with more contaminated firewater being pumped away from the area and taken for disposal.

"EPA advice to avoid contact with the waters there remains in place. At this stage," the environmental regulator said, also assuring the public that the smoke no longer poses any risk.

Local media revealed that the industrial facility was operated by the chemical blending manufacturer ACB Group, where a worker died in a chemical explosion last year.