EIGHT prisoners, including two Australians, have been executed by firing squad in Indonesia, defying international condemnation.

The convicted Australian drug smugglers Andrew Chan, 31, and Myuran Sukumaran, 33, were among those put to death on Tuesday evening.

Four Nigerians, an Indonesian and a Brazilian national were also executed, reports say.

Nine inmates, all convicted on drug charges, were given 72-hour notices over the weekend that they would be executed by a firing squad, prompting a flurry of last-minute lobbying by foreign leaders.

Eight faced separate police firing squads at an execution site outside the gates of Pasir Putih prison on the island of Nusa Kambangan off the southern coast of Java, according to the attorney general's office.

The United Nations has argued that their crimes - ranging from possession of 72kg (11.3 stone) of marijuana to heroin trafficking - are not egregious enough to warrant the ultimate punishment.

Indonesian authorities are yet to officially confirm the executions have been carried out.

Earlier, Jakarta rejected last-ditch pleas from around the world for clemency to be granted the drug traffickers from Nigeria, Australia, Brazil and Indonesia, ordering their mass execution to proceed within hours.

The authorities granted a stay of execution to Mary Jane Veloso, 30, a Philippine citizen, so they could review her conviction for smuggling heroin into Indonesia in 2010.

Veloso, was arrested in 2010 after she arrived in Indonesia with 2.6kg of heroin hidden in her suitcase. The woman's family maintains that she was duped into carrying the drugs, hidden in a suitcase, by a drug syndicate.

Eight people were executed but not Mary Jane," Tony Spontana, a spokesman for the attorney general's office, said.

He said the delay came in response to a request from Manila after a drug courier gave herself up to police in the Philippines on Tuesday.

The mass execution was the second in Indonesia this year. In January, five foreign drug convicts and one Indonesian convicted of murder were executed on the island.

Hours before the expected executions, crowds gathered in cities across Australia to hold vigils for two nationals Sukumaran and Chan holding placards and calling for the nation to respond strongly to its neighbour if the executions proceed.

Australian foreign minister Julie Bishop criticised Indonesia's "chaotic" handling of the executions, saying there would be "consequences" if the killings were carried out.

"I think the ghastly process that the family have been put through today just underscores how chaotic this has been," Ms Bishop said.

"They do deserve respect and they do deserve to have dignity shown to them at this time of unspeakable grief. But that doesn't seem to have been extended to them at this time."

A dozen ambulances, nine carrying coffins, were earlier driven onto the ferry to Nusakambangan. On the dashboard of one ambulance was a piece of paper bearing the name of Veloso.

Over the weekend, authorities asked the nine inmates - the two Australians and Veloso, as well as four Nigerian men and one man each from Brazil and Indonesia - for their last wishes and gave them a 72-hour notice of their executions. Authorities granted Australian Chan's final wish, which was to marry his Indonesian girlfriend at the prison.

Philippine President Benigno Aquino said on Tuesday that he had made one last appeal to the Indonesian government to spare Veloso, arguing that she could be a vital witness in prosecuting drug syndicates.