Burning embers are being blown towards homes at Springwood in the NSW Blue Mountains, where an emergency warning has been issued.
"The message will be prepare for embers, work with the firefighters and shelter in place where appropriate," Rural Fire Service Commissioner Shane Fitzsimmons told reporters.
The RFS said fire intensity had picked up in Faulconbridge and Springwood around Chapman Parade, Grose Road and Douglas Road along with strong, gusty winds.
Additional firefighters are being sent to the area and residents are being sent telephone alerts.
Springwood resident Rae Tebbutt said the atmosphere was tense.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Everyone is terrified. I've got three friends who have lost everything," Ms Tebbutt told AAP.
"Our car's packed up. All our photos, personal items, the laptop, documents are all ready to go."
Winamalee High School year 10 student Zara Barger, walking her dogs in Springwood, was experiencing her first bushfire after moving from Sydney this year.
"It's a huge worry with the fire trucks roaring past," she said.
