Firefighters were hoping to use calmer and cooler temperatures yesterday to control fires across the state, but blazes in and around the Blue Mountains flared up.
Crews were redirected from back burning operations to protect more than 100 homes in Bell, Dargan, Berambing and Bilpin that are now under threat.
The RFS issued its highest emergency warning for fire burning between Lithgow and Bilpin and closed roads in the area. It has also issued an emergency warning for Springwood, where 193 properties have been destroyed.
RFS deputy commissioner Rob Rogers said the fire "is by no means contained" and that it had "kilometres and kilometres of fire front".
He said local temperatures would likely warm up today and winds could strengthen tomorrow.
More than 300 properties in the lower Blue Mountains were damaged or destroyed by bushfires on Friday, the RFS said. Eighty bushfires are raging in the state.
On Friday the Insurance Council of Australia said there had already been 550 claims totalling A$30 million ($34 million), with the number expected to rise sharply.
A firefighter has undergone surgery for face and neck burns and a colleague is recovering after being taken to hospital on Friday.
About 200 firefighters from Victoria, South Australia, Tasmania, the ACT and Queensland are helping New South Wales firefighters. AAP
