The New South Wales Rural Fire Service said a military training exercise sparked the largest of the wildfires that have ravaged the Australian state.
Fire investigators found that a massive fire near the city of Lithgow, west of Sydney, began on 16 October at a nearby Defence Department training area, and that the blaze was started as a result of live ordnance exercises at the army range.
The fire has scorched 47,000 hectares (180 square miles) and destroyed at least three houses, but no injuries or deaths have been reported.
The Defence Department declined to comment on the investigators' findings, but confirmed earlier that an explosive ordnance training exercise was conducted on that date
More top news
Two people have been arrested after a car crashed into pedestrians in Marbella.
A missile launched by North Korea has landed in the Sea of Japan, according to the Japanese Government.
A band of thundery rain moves northwards overnight.