Cilacap, Indonesia: Two Australian drug smugglers were taken on Wednesday to an Indonesian island where they will be executed despite frantic diplomatic efforts to save them, as Prime Minister Tony Abbott said Australia was “revolted” by their looming deaths.

Andrew Chan and Myuran Sukumaran, the ringleaders of the so-called “Bali Nine” drug smuggling gang, were woken and given a few minutes to get ready before leaving Bali’s Kerobokan jail in the early hours, said justice ministry official Nyoman Putra Surya.

The men, sentenced to death in 2006 for trying to smuggle heroin out of Indonesia, said “thank you” before leaving. “We handcuffed them and they were quiet,” he added.

Michael Chan attempted to see his brother Andrew before the transfer, but prison officials denied him entry, with Surya saying the decision was taken because “today is not visiting day”.

More than 200 police and soldiers as well as a water cannon were stationed outside the Bali prison as the men, in their early 30s, were driven out through a scrum of journalists.

The pair were flown to Cilacap on Java island, on a chartered flight accompanied by military aircraft.

Two armoured vehicles escorted by elite police then boarded a boat at the local port which crossed to Nusakambangan island, home to several high-security prisons, where the pair will be executed, an AFP reporter at the scene said.

The men recently lost their appeals for presidential clemency, typically the last chance to avoid the firing squad. Officials have yet to announce a date for their executions, but the transfer indicates it is imminent.

They are among several drug convicts, including foreigners from France, Brazil, the Philippines, Ghana and Nigeria, who have lost their clemency requests and are expected to be put to death at the same time on Nusakambangan soon.

Several are already on Nusakambangan, and attorney-general Mohammad Prasetyo said a Nigerian was also transferred to the island on Wednesday. A Philippine woman, whose legal challenge to her sentence is currently being heard, is due to be transferred from central Java.

Prasetyo said final preparations, such as training the firing squads, were still being made before a date could be set for the executions. Authorities must give convicts 72 hours’ notice before they are executed.

Abbott, who has repeatedly called for Jakarta not to proceed with the executions, said Australians were sickened by the developments.

“We frankly are revolted by the prospect of these executions,” he said, adding that “right now millions of Australians are feeling sick in their guts”.

Abbott said he hoped there might be a “change of heart in Indonesia”, but added: “What I don’t want, though, is to hold out false hope.”

However, he added: “I hope that even at this late hour, the better angels of the Indonesian peoples’ nature will reassert themselves.”

Foreign Minister Julie Bishop told parliament she had spoken to the families of Chan and Sukumaran and they were “devastated”. Attorney-general George Brandis said the government had made at least 22 representations to Indonesian officials since January.

President Joko Widodo has been unswayed by the barrage of international appeals, insisting that Indonesia is facing an “emergency” due to rising narcotics use. Prasetyo reiterated the government’s tough line.

“We want to ... send a message to all parties and to the international community that Indonesia is working hard to battle drug crimes,” he said.

Indonesia executed six people including five foreigners in January, sparking a diplomatic storm as Brazil and the Netherlands — whose citizens were among those put to death — recalled their ambassadors.

The Australians’ lawyers have launched a series of last-ditch legal bids to stop the executions, urging authorities not to put the men to death while the legal process is still ongoing.

Brazil and France have also ramped up pressure, with Paris summoning Indonesia’s envoy and the Brazilian president refusing to accept the credentials of the new Indonesian ambassador.

A district court near Yogyakarta, on Java island, decided Wednesday that the Supreme Court should rule on the Filipina’s application for a judicial review of her case since it did not have the authority.

However, officials have previously insisted that an appeal for presidential clemency is the last chance to avoid execution.