NSW girl, 2, burnt during explosion

A two-year-old girl has been burnt in the face during a fiery explosion at a property near Gunnedah, in northeast NSW.

The toddler was taken to Tamworth Base Hospital in a stable condition after authorities were called to Prairie's Road in Kelvin about 6pm on Wednesday.

She's since been transported to a hospital in Sydney for specialist treatment, a spokesman for the Hunter Region Westpac Rescue Helicopter said on Thursday.

It's not yet known what caused the small explosion, which is understood to have been set off by a fire at the property.