Winds and temperatures have eased across NSW this weekend but the Rural Fire Service (RFS) has warned that unmanned drones may hamper ongoing firefighting efforts.
An RFS spokesman told AAP the service had received reports of an unapproved drone hovering around Springwood, where a major bushfire has destroyed nearly 200 homes.
He said if the reports were confirmed the service would be forced to put aerial firefighting operations in the area on hold.
"The drone can obviously interfere with their operations," the spokesman said.
The Civil Aviation Safety Authority (CASA) issued a warning on Saturday morning after officials saw video footage of a remotely piloted aircraft being operated above the State Mine Fire that stretches from the Blue Mountains to Lithgow.
"Flying an unapproved remotely piloted aircraft near firefighting aircraft, firefighters and firefighting vehicles is dangerous," CASA aviation safety director John McCormick said.
Three fires continued to burn at a watch and act level in the Blue Mountains on Saturday - the Springwood, State Mine Fire and Mount York Road blazes.
A grass fire at Timbarra in the state's north has been downgraded to advice level.
A total 50 fires were burning across NSW on Saturday afternoon including some 20 uncontained fires.
Firefighters have taken advantage of the cooler conditions to step up backburning efforts, which have sent smoke across the Blue Mountains and Southern Highlands.
One firefighting pilot has died so far this bushfire season, though there is no suggestion a drone was involved in that incident.
Father-of-three David Black died when his Dromader aircraft crashed while he was water-bombing fires in the state's south on Thursday morning.
The 43-year-old from Trangie, NSW, has been remembered as a pilot "at the top of his game".Scores of firefighters at Penrith Base Camp gathered to observe a moment's silence for Mr Black on Saturday morning.