More than a dozen unexploded bombs weighing up to 992lbs (450kg) each are believed to be buried on two islands in Australia's far north where endangered turtles nest.
The Australian Defence Department is spending AU$2.2 million (US$2.18m) to clear Bare Sand and Quail islands of unexploded bombs buried when the site was used as an aerial bombardment practice range for 40 years.
Thousands of bombs were dropped on the islands -- 27 miles (44km) west of Darwin -- from World War II until 1979.
The islands are an important nesting site for the flatback sea turtle endemic to the continental shelf of Australia.
Contractors G-tek Australia dug up 51.8 tons (47 tonnes) of scrap metal and detonated eight unexploded bombs weighing up to 992lbs (450kg) last dry season but project officer David Thomas suspects there could be double the number of bombs still buried.
"I would be very surprised if there weren't more given the first eight have been less than a meter [three foot] deep -- there is probably twice as many as that," he said.
The Defence Department said no flatback turtles had been harmed during the exercise and the bomb clean-up should be finished by November.