The Royal National Park has been closed as firefighters battle two bushfires burning out of control near Wattamolla on Saturday afternoon.

Multiple Rural Fire Service crews and aircraft are responding to the blazes, burning in the park along Sir Bertram Stevens Drive. 

Fire crews are unsure how many people are in the park, which is a popular weekend destination, but have warned visitors to leave "only if the path is clear" or if directed by emergency services.

People at Little Garie, Garie, North Era, South Era or Burning Palms have been advised to remain in place by the NSW RFS.

The RFS has issued an emergency warning, and is sending telephone warnings to people in the area. Visitors have been advised to head to the beaches, which "may offer safety".

The following entry points are closed:

Follow our updates below and check www.rfs.nsw.gov.au for advice.

At this stage the RFS is unaware of any direct threats to properties, but warns residents in the Bundeena area to "watch and act," and enact their bushfire survival plans. 

The fire is emitting large amounts of smoke, which can be seen from the Illawarra. 

It is understood a surfing carnival is taking place within the park, but RFS do not believe there is any threat to visitors at the event at this stage.

Meanwhile, the RFS has issued a "watch and act" alert for a bush fire burning out of control south-west of Sydney at Long Gully Road, in Bannaby.

While firefighters and aircraft are working to slow the fire, the weather conditions are causing fires to "burn erratically" and become "difficult to control". 

Isolated rural properties in the area of Alders and Crees Road and Bennaby Road may soon come under threat, the RFS warns.

Firefighters are also continuing to battle with a bushfire that's burnt more than 33,000 hectares in the Pilliga Forest between Coonabarabran and Narrabri.

The fire is at an advice level with no homes are under threat, but residents are being urged to monitor conditions.

Firefighters are currently conducting back burning operations in the area and the Newell Highway has been shut between Narrabri and Coonabarabran and is likely to remain closed on Saturday.

Further south, firefighters from the ACT have been sent across the NSW border to protect houses threatened by a bushfire in the Southern Tablelands.

Three heavy tankers, backed up by smaller crews, were deployed to the 274 hectare Braidwood blaze on Saturday morning after it burned through the night.

"Their objectives are to protect properties, attack and contain the main fire and contain spot fires," the ACT Emergency Services Agency said.

More to come

with AAP