Emergency crews are responding to an out-of-control fire at one of Australia’s two remaining oil refineries, which supplies 10% of the country’s fuel.

The fire at Viva Energy refinery in Geelong, 65km southwest of Melbourne, was described as “significant”, the ABC is reporting.

Victorian emergency services are responding to the blaze, with up to 17 fire vehicles sent to help.

Fire Rescue Victoria said it responded at 11.15pm (local time) last night after multiple reports of explosions and flames at the refinery.

“The fire is not yet under control, although it is currently contained to the plant,” it said, adding that the fire involved “liquid fuels and gases”.

No one had been hurt in the fire at the refinery, which supplied 10% of Australia’s fuel and 50% of Victoria’s, news.com.au reported.

However, the fire had sent smoke billowing across the region, with a sweeping “watch and act” warning for tens of thousands of residents, the Geelong Times reported.

A wind change overnight led authorities to urge residents to shelter indoors immediately, but the Country Fire Authority (CFA) downgraded the threat this morning.

Motorists were also told to stay away from the area.

Petrol production impacted - refinery boss, minister

The fire would affect petrol production, Viva Energy chief executive Scott Wyatt said.

“The units that are impacted are in the petrol part of a collection of units that do make petrol,” he told the Australian Financial Review.

The priority was to make the site safe for workers.

“We’ve still got work to do, as Fire Rescue Victoria have said, over the course of the morning, to really contain and extinguish the fire, make it safe, understand what damage has occurred, and understand how we can safely restore production across the site.”

Federal Energy Minister Chris Bowen told the ABC that it wasn’t clear how fuel supplies would be affected, but the fire “will have an impact”.

“I’m sure petrol production will continue, but it may be impacted for some time.”

‘Not suspicious’ - fire chief

The “quite ferocious” fire started in the part of the refinery where motor gasoline was produced, with 50 firefighters sent to put it out, Fire Rescue Victoria assistant chief Michael McGuinness said.

“There’s been some sort of leak, there’s hydrocarbons, flammable liquids which very readily caught fire”, he told the ABC.

“It was burning in an area of approximately 30 metres by 30 metres. There have been several small explosions.

“The fire went from a small fire, through several explosions, to be quite a large and intense fire.”

The fire would be investigated, but was not being treated as suspicious, he said.

“It may very well be just a malfunction of a piece of pipework or a valve.”