Indonesia executes four

Indonesia deputy attorney-general Noor Rachmad said the four were shot dead shortly after midnight on Central Java's Nusa Kambangan prison island, during a thunderstorm.

Amnesty International condemned the executions, with the group's Rafendi Djamin labelling them "a deplorable act".

The UN Secretary-General Ban Ki-moon and the European Union had also voiced opposition to Indonesia's intentions in recent days.

18 executions since Widodo's election

It was the third set of executions under President Joko "Jokowi" Widodo. He was elected in 2014 on promises to improve human rights. Since then, 18 convicts - mostly foreigners - have been put to death.

Lawyers and rights groups had raised serious doubts about the conviction of one of the Nigerians, Humphrey Jefferson, who is to be buried in Indonesia.

Rachman said executions were "only aimed at halting drug crimes."

He said decisions about the executions of 10 further prisoners would be announced later. He added that remaining executions would proceed "in stages" but declined to give a timeframe.

Reprieve the rest, urges Amnesty

"Any executions that are still to take place must be halted immediately," said Amnesty's Djamin.

"The injustice already done cannot be reversed, but there is still hope that it won't be compounded," he added.

In Nigeria's capital Abuja, protestors had gathered at the Indonesian embassy, where security had been tightened, to urge Indonesia to halt the state killings.

Diplomatic outrage erupted in April last year when Indonesia put to death eight drug convicts, including two Australians.

ipj/kl (AP, Reuters, AFP)