The Rural Fire Service (RFS) is warning residents in fire-affected areas not to become complacent, after the downgrading of warnings for major blazes burning across New South Wales.

Cooler conditions across the state’s south-east today are expected to give fire crews a chance to contain several large fires still burning out of control.

But as the immediate threat passed overnight, a local mayor expressed his dismay after an investigation blamed the Defence Department for one of the fires.

Defence is yet to accept the finding by RFS investigators that artillery training on October 16 caused the state’s largest bushfire at Lithgow in the Blue Mountains.

The fire has burned almost 48,000 hectares, destroyed three homes and threatened a number of villages around Bilpin.

Blue Mountains Mayor Mark Greenhill says although there was not a total fire ban in place that day, Defence should have realised conditions were not ideal.

“It’s done damage to my community and it just shouldn’t have happened. Not happy at all,” he told the ABC’s 7.30 program.

“There’s the damage it does to the community and the stress it causes. There’s the damage it does in terms of the risks taken by the firefighters.

“There’s the damage it does in terms of the costs to the community of fighting that fire and let’s not forget it’s still going, it’s still out there.”

Defence said in a statement it had been conducting live ordinance exercises at the Marrangaroo Training Area the day the fire started.

It said it was cooperating with police and investigators as well as conducting its own inquiry.

Overnight, the RFS was trying to put in a 20-kilometre containment line to halt the progress of the blaze, known as the State Mine fire.

It was one of several blazes that had been subject to an emergency warning during extreme temperatures and wind gusts yesterday.

Fire crews worked through the day to reinforce containment lines around the largest fires in the Blue Mountains, Lake Macquarie and the Southern Highlands.

But despite all being downgraded to watch-and-act alerts, RFS Commissioner Shane Fitzsimmons said the danger was not over.

“We do need to be crystal clear here there is still a lot of fire across the Blue Mountains area that is very active,” he said.

Back-burning operations continued and crews were working quickly to put out any new outbreaks that flared up because of spot fires.

Residents urged not to be complacent

Residents of the Blue Mountains and Hawkesbury have been allowed to return to their homes, and some schools will re-open today.

But RFS spokesman Andrew Luke is warning residents not to become complacent despite the downgraded alerts.

He says more strong winds are predicted later.

“While the immediate threat for (Wednesday) evening has certainly passed, with the southerly winds that are forecast and are affecting a number of fire grounds into (Thursday), they’ll pick up and strengthen again,” he said.

“So there is the possibility, particularly on the Bells Line of Road, where properties weren’t under effect, [that those properties] could very well become endangered over the coming days.”

Mr Fitzsimmons said the winds expected today would be particularly dry.

“While the temperatures will moderate right down into the 20s – a welcome relief to what we saw (Wednesday) – the winds still will be strong. We are talking 45 to 50kph,” he said.

“That is going to be particularly problematic because there is no moisture in this change and it is going to be very dry air.”

As of Wednesday night, there was about 30 uncontained fires burning across the state.

8yo boys caught trying to start fire

Meanwhile police have caught two eight-year-old boys trying to start a fire in the Hunter region.

Police say they were called by a member of the public who claimed to have seen the boys in a vacant block in East Maitland, trying to set fire to a small pile of dry leaves and grass about 6.30pm AEDT.

Officers arrived and allegedly found the boys with a lighter which was later found to be inoperable.

The boys were taken home to their parents and officers completed child-at-risk notifications.

No charges will be laid due to the ages of the boys.

Earlier this week two boys aged 11 and 15 were charged over a fire which ripped through Port Stephens last week.