Guards at Indonesia's Nusakambangan prison island - photo from BBC video
Indonesia has executed four drug convicts and has ten more on death row awaiting execution. One Indonesian and three Nigerians were killed by firing squad at possibly 06:00 local time today.

The international organization Amnesty International has called the executions "deplorable acts" and say they go against international and local law.

Last year, Indonesia executed 14 drug convicts. Most of them were foreigners. Following the execution of two Australians in April 2015, the Australian ambassador to Indonesian left the country for five weeks in protest. 

Before he was elected in 2014, President Joko Widodo vowed to become very strict against drug convicts. This is the third round of executions since he took power.

There are now ten prisoners who wait on death row to be executed on Indonesia's Nusakambangan prison island: three Indonesians, a Pakistani, an Indian, two other Nigerians, and two Zimbabweans. 

drug convict - someone who has been found guilty of having / selling illegal drugs
to execute - to kill a prisoner, as a government or other organization
death row - an area in prison where prisoners wait to be executed
firing squad - a form of execution where prisoners are shot by many soldiers with guns
deplorable - extremely terrible
ambassador - a political representative of one country that lives in another country
in protest - to declare / show severe disagreement 

to vow - to publicly promise
round - one session