Story highlights Australia PM: We hate drug crime, but we hate capital punishment, too

Prisoners will be notified 72 hours before execution is to take place

Two men to be shot are considered the leaders of failed heroin-smuggling plot

(CNN) Two Australians held by Indonesian authorities for nearly a decade appear to be just days away from execution by firing squad.

Myuran Sukumaran and Andrew Chan, members of the so-called "Bali Nine" sentenced on drug smuggling charges, were transferred Wednesday from prison to a maximum security facility where they will be isolated before being put to death.

Australia has repeatedly appealed for clemency for the pair. They have been jailed since April 2005 for a failed bid to smuggle more than 8 kilograms of heroin from Bali to Australia.

Australian death-row prisoners Andrew Chan (left) and Myuran Sukumaran in file image from 2011.

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Nusakambangan Island, Indonesia

Australian Prime Minister Tony Abbott on Wednesday said "Australians are feeling sick in their guts at the prospect of execution for these two."

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