Firefighters from the NSW Rural Fire Service (RFS) and National Parks are working to contain a blaze on the Sandstone Cave Walking Track near Dandry in the Pilliga Nature Reserve.

Authorities were alerted at around 3:40 pm today (Wednesday 26 FebruaryP. 

By 8.30pm the fire had burned 1059 hectares and was still not under control.

The fire is not far from the Newell Highway which has been closed.

Earlier in the afternoon ten firefighters from the NSW RFS were attending the blaze with five trucks accompanied by four firefighters from National Parks.

Further crews were called in to assist.

Authorities are asking the public to stay away from the area.

An aerial view of the fire near the Sandstone Caves taken earlier on 26 February. IMAGE: RFS

The RFS is still working to determine the cause of the blaze.

The Sandstone Cave Walking Track in the Pilliga Nature Reserve will be closed until further notice due to the fire.