A 16-year-old boy has been charged in relation to a bushfire at Glenrock State Conservation Area, near Newcastle.
Fire crews battled a number of fires in the conservation area between Dudley and Merewether Heights just before 3pm (AEST) on Thursday.
Police were called to assist and arrested four teenage males about 4.30pm, taking them to Belmont Police Station.
A 16-year-old boy has been charged with two counts of causing or setting fire to a property and two counts of intentionally causing fire, and will appear in court on October 8.
The remaining teenagers were released pending further inquiries.
The fires, which affected about 40 hectares of bushland, have been contained and police investigations continue.