A Darwin-based RAAF airman suffered serious burns when the portable toilet he was inside exploded at Rockhampton Airport in central Queensland.

"The member received immediate first-aid treatment and was evacuated to the Rockhampton Hospital with third-degree burns to his upper body," the Defence Force's Brigadier Bob Brown said.

A spokeswoman for the Department of Community Safety says the injured man may have lit a cigarette in the toilet.

"There was some sort of explosion in a portaloo. It's believed the man was lighting a cigarette at the time," she said.

Authorities say he had been involved with the Talisman Sabre military training exercise.

The man will be flown to a Brisbane hospital for specialist treatment.

An investigation is underway into the cause of the blast.

ABC/AAP