Sydney was cloaked in a haze of smoke pollution on Wednesday as firefighters battled through tough conditions that are expected to continue deteriorating.

The New South Wales Rural Fire service has issued widespread total fire bans for Thursday, with hot and windy conditions expected to worsen across the state.

An RFS spokesman on Wednesday evening said there were reports of property damage in the 6000-hectare Three Mile blaze near Wisemans Ferry.

“We’ve had reports of property damage in the area, we can’t confirm exactly what that was,” an RFS spokesman said.

An emergency alert was issued for the nearby Gospers Mountain blaze on Wednesday afternoon. The Gospers Mountain fire has burnt through more than 230,000 hectares in the Wollemi National Park.

At 6:15pm there are 137 fires burning, 81 are not contained. 3 fires are at Emergency Warning & a further 7 at Watch and Act. More than 2,500 personnel are working to slow the progress of the fires ahead of worsening conditions tomorrow. #nswfires #nswrfshttps://t.co/to0I5jPHQs pic.twitter.com/xb4HzOywkM — NSW RFS (@NSWRFS) December 4, 2019

The RFS spokesman said there was a chance the two fires could merge as conditions deteriorated on Thursday.

“It’s a possibility, we’ve already seen a large number of fires merging this fire season,” he said.

“Conditions are so dry that putting fires out is very challenging at the moment. We are just trying to establish containment lines.”

Emergency warnings were in place on Wednesday evening for the Gospers Mountain fire as well as fires near Putty and Paterson.

Strong westerly winds forecast for Thursday could push those three fires further east, putting more properties at threat.

“We are asking people in the vicinity of these fires to have a plan and to know what they will do if that happens,” an RFS spokesman said.

The RFS says bushfire smoke is expected to linger in the Sydney basin until the weekend.

Queensland residents told to leave

A section of the Gore Highway south-west of Millmerran in Queensland was closed because of a raging bushfire on Wednesday afternoon.

Residents in the rural towns of Forest Ridge and Cypress Gardens, between Toowoomba and Goondiwindi, were told to leave immediately.

The bushfire was fast approaching properties, and firefighters urged residents to leave and head north-east to the town of Millmerran.

But the highway between the BP service station at Captains Mountain through to Cypress Garden was closed to all traffic.

This is the Gore Highway south west of #Millmerran where an out of control bushfire is threatening dozens of homes @WINNews_TWBA @10NewsFirstQLD #qldbushfires pic.twitter.com/UBZcIROD1L — Caitlin Crowley (@Cait_Crowley) December 4, 2019

A statement on the Queensland Rural Fire Service website said the fire was expected to have a significant impact on the community.

As of 3.15pm, there were 11 fire crews attempting to control the blaze, with another 13 heading to the scene.

An evacuation centre was opened at Millmerran Community Cultural Centre, 42 Walpole Street, Millmerran.

Smoke forecast to linger in Sydney

Heavy bushfire smoke smothering Sydney and other parts of NSW was forecast to linger into the weekend.

Firefighters faced another tough day of windy and dry conditions on Wednesday with total fire bans in place for the greater Hunter, the northern slopes and north-western regions of the state.

The NSW Rural Fire Service on Wednesday said the “heavy smoke” would be noticeable in Sydney for several days.

And Sydney now ranking No. 11 as worst polluted major cities, according to AirVisual: pic.twitter.com/7TkgVMLeww — Peter Hannam (@p_hannam) December 4, 2019

“Very heavy smoke is affecting the Sydney area. It is being blown from large fires near Warragamba Dam,” the RFS said in a statement.

“Smoke is also affecting areas including the north coast, Hawkesbury, Wollondilly, Queanbeyan and Shoalhaven areas.”

The Bureau of Meteorology said the smoke would stick around until Saturday.

#Sydney is 'brown town' this afternoon with smoke casting a brown haze over the city. Smoke is forecast to linger overnight and into Thursday. Smoke will also affect areas east of fires in other parts of the state due to westerly winds. Smoke health info: https://t.co/fXRR0BgTIL pic.twitter.com/vmHlL4aE7N — Bureau of Meteorology, New South Wales (@BOM_NSW) December 4, 2019

Lingering smoke could be “unhealthy for sensitive people, and could cause symptoms, especially in people with heart or lung disease”, the state’s environment department said.

Air quality levels were hazardous in parts of Sydney on Wednesday morning.

There were 116 fires burning across the state on Wednesday with 60 uncontained, and there were more than 2,200 firefighters in the field.

Firefighters worked through Tuesday night to protect houses from the 47,000-hectare Currowan blaze north of Batemans Bay on the south coast.

“Firefighters overnight worked to protect a number of properties in coastal communities,” the RFS said. “Easing conditions have seen the threat to homes reduced.”

The Currowan blaze – which destroyed at least one home – was downgraded to a “watch and act” alert level.

There were six other fires burning at a watch and act level on Wednesday afternoon near Willawarrin, Kurri Kurri, Putty and Wisemans Ferry, as well as separate blazes east and west of Wollombi.

Perth bushfire threat amid heatwave

Meanwhile, a bushfire was posing a possible threat to lives and homes in Hazelmere, north-east of Perth, on Wednesday as the state’s heatwave continued.

A “watch and act” alert was issued for an area between Midland Road, Talbot Road, Roe Highway and Helena Valley Road, but was soon downgraded to “advice”.

Authorities earlier on Wednesday advised that a bushfire burning at Forrestdale in Perth’s south-east had been contained and the warning level downgraded to “advice”.

The blaze burnt through about 47 hectares with 90 firefighters tasked to the area at the height of the emergency.

Total fire bans were declared for inland areas between Lancelin and Waroona with the temperature set to hit 36C in Perth.