Al Arabiya could not verify the provenance of the footage or the identity of the perpetrators and their victims.
The video was posted on Tuesday but it was not clear where or when it was filmed.
However it does clearly show a summary execution and torture, apparently being carried out by government supporters.
Syrian opposition writer Habib Saleh told Al Arabiya that the scenes shown in the video are equal to the unprecedented violence perpetrated by the Mamluk dynasty between the 9th-19th century AD.
Saleh strongly denounced such operations and considers it barbaric and brutal. It is his opinion that such acts could amount to genocide crimes.
The video was posted on YouTube by the media office of the Damascus-based rebel First Brigade.
The office said it had been sourced from a captured member of the ‘shabbiha’, a pro-government militia made up mainly of members of Syria’s minority Alawite sect.
The graphic video begins with a group of captive men huddled against a wall in a room filled with broken masonry. Most wear jeans and t-shirts pulled up over their heads, covering their faces.
Five armed men in camouflage uniforms and holding assault rifles stand behind them, one of whom turns to the camera to grin and wave. Several captives are led out the room, leaving two men huddled against the wall.
A tall, bearded soldier with dark sunglasses and a black Nike baseball cap lightly slashes at the men’s backs with a knife. Two others hand their guns to their comrades and unsheathe knives.
A close-up shows cuts through one victim’s blue sweater, revealing his bare skin. Blood starts to flow down his back as the other victim falls to the ground.
The soldiers show off for the camera, smiling for close-up shots before they start stabbing the men more deeply and violently in the back and side.