The Defence Department admits an army exercise has sparked another grass fire, this time in Queensland’s Wide Bay.

Defence has been forced to apologise for starting the biggest blaze in the current New South Wales fire crisis.

A live weapons exercise sparked the State Mine Fire near Lithgow, north-west of Sydney, which destroyed homes and blackened almost 50,000 hectares.

Today, the Army has admitted a live weapons exercise also caused a fire near Tin Can Bay in Queensland’s Wide Bay region.

The blaze started on Monday before a total fire ban was put in place across the region.

The Defence Department says one square kilometre has been burnt and no equipment or property has been damaged.

A fire two months ago at the Townsville field training area in north Queensland has also been linked to an army exercise, as well as a weekend blaze near Port Augusta in South Australia.