Two young men were arrested at a petrol station in Sydney’s west over an out-of-control bushfire that took more than 200 firefighters to control on Friday.

Two males, aged 17 and 21 years old, were arrested and were assisting police with inquiries.

Hundreds of firefighters were forced to to battle a “ferocious”, out-of-control bushfire in western Sydney that destroyed at least one home and earlier threatened several others at Cranebrook before spreading to the neighbouring suburb of Llandilo.

The blaze began alongside a nature reserve in the Cranbrook area at 2pm on Friday before spreading to consumed about 300 hectares in surrounding suburbs, with properties, schools and nursing homes evacuated, police say.

Llandilo resident and business owner Kim Hamilton told AAP the area “often goes up” because of serial firebugs.

Rural Fire Service (RFS) Deputy Commissioner Rob Rogers also said there were reports two Cranebrook properties had been damaged earlier in the afternoon.

“Confirmation of that, we’ll obviously have a look at as soon as time permits,” Deputy Commissioner Rogers said.

“But right now we’re just trying to save as much as we can and halt the progress of this fire.”

.@NSWRFS crews on scene of a fire near Vincent Road at Cranebrook
Photo by Luke Buttigieg pic.twitter.com/4Stjo91KPi

— ABC Sydney (@abcsydney) November 4, 2016

Authorities said the blaze quickly spreading to nearby suburbs, but an emergency warning for Llandilo and Londonderry near Penrith, had been downgraded to a Watch and Act alert.

Deputy Commissioner Rogers said the fire burned “extremely ferociously in high winds”, but was later contained.

“It’s moving in a south-easterly direction from the Llandilo area … which is the areas of 7th, 8th, and 6th avenues, out through to 9th Avenue, and then into open bushland,” Deputy Commissioner Rogers said.

“We’ve got a lot of aircraft on it.”

Emergency Warning issued by @NSWRFS for the fire at #Llandilo & #Londonderryhttps://t.co/CEJoWqKsEN
Video by Luke Buttigieg pic.twitter.com/gm6eo38nx5

— ABC Sydney (@abcsydney) November 4, 2016

He said authorities had been concerned the fire could head “towards more urbanised areas a few kilometres in that south-easterly direction”.

**BREAKING** Two teens arrested at nearby petrol station over the fire in Cranebrook. https://t.co/deXxm5IoEL #7News pic.twitter.com/wxdlWDOm4g

— 7NEWS Sydney (@7NewsSydney) November 4, 2016

Motorists were also urged to avoid Cranebrook where many roads were closed.

Earlier in the day a man’s utility was engulfed by the fire while parked beside nearby bushland at Cranebrook.

“It [the fire] moved like a rocket” he told 702 ABC Sydney.

Another man said he managed to extinguish flames at the front of his house after he ran home from work.

“My mother-in-law rang saying ‘get out, the house is on fire’ and I come to this,” he told the ABC.

Homes on the NSW south coast also came under threat when firefighters lost control of a hazard reduction burn in the Callala Bay area, near Nowra.

That blaze came within 100m of properties before being downgraded in the evening.

– with ABC