Isis bazooka
A still from an IS video claiming to show the execution of a Sunni al-Sheitaat tribe teenager. - Raqqa is Being Slaughtered Silently/YouTube

Islamic State (Isis) has posted a video showing the execution with a bazooka of a young member of the Sunni al-Sheitaat tribe in Syria's eastern Deir Ezzor (or Deir al-Zour) province.

The clip, which was shot on 20 May according to the Raqqa is Being Slaughtered Silently blog, shows an armed group of IS fighters addressing a man tied to a pole. A jihadist asks the teenager to say his name, where he is from, and what he did. The young man says his name is Ibrahim al-Sharida from the city of Abu Hamam in Deir Ezzor and he's from the al-Sheitaat tribe.

He admits to killing two IS soldiers in Hai Sanour with a rocket-propelled grenade. The IS fighter says the boy "is an enemy of God" for killing the IS soldiers and that they will avenge their deaths. In an eye-for-an-eye retribution, the extremists kill the teenager by firing a bazooka from a distance at him.

The Raqqa is Being Slaughtered Silently blog, a collective platform of activists secretly reporting on IS massacres in Syria, said the extremists depicted in the video are foreign fighters from Tunisia and Morocco.

In 2014, the al-Sheitaat tribe attempted a rebellion against IS rule in Deir Ezzor. The jihadists crushed the revolt in three days, killing, beheading and crucifying members of the tribe. Around 900 people were estimated to have been killed in the bloodiest single atrocity committed by IS in Syria.

According to reports, IS killed eight members of the al-Sheitaat tribe in the recently conquered central city of Palmyra.