Idris Elba depicts an evil warlord in the newly released trailer for upcoming Netflix movie 'Beasts of No Nation'.

The 42-year-old actor plays the central character - known as Commandant - who is a leader of child soldiers and the story follows his attempts to force a young boy to join the mercenary fighters during a civil war in Africa.

Dramatic scenes from the teaser show Idris dressed in camouflage clothing as he urges the young Agu, played by Abraham Attah, to commit murder.

He says: ''These are the ones that killed your father, that is your family's blood.''

The drama is based on the eponymous named book by Nigerian/American author Uzodinma Iweala that was published in 2005 and which received wide-spread critical acclaim.

Directed by Cary Fukunaga, it is the first original film to be released globally by Netflix and is set to premier at Venice Film Festival in September.

However, some movie theatres are boycotting the project because it will debut on streaming site at the same time as its cinema release.

'Beasts of No Nation' opens in selected cinemas and on Netflix on October 16.