Most likely ruthless Chechens.
Via Long War Journal:
A video of jihadists executing a group of Syrians in the city of Aleppo has emerged. The execution is carried out by Russian-speaking fighters, and one of those to be killed was said to be mentally ill.
The graphic video was published today on the Facebook page of a group known as the Syrian Center for Documentation. The group claimed that civilians, including children, were among those killed. Although the date and exact location of the execution has not been disclosed, the Syrian Center for Documentation indicated that it took place in Aleppo.
In the video, a number of well-armed fighters are seen moving civilians into a large room. A group of young and middle-aged males appears arranged in a line, while others are huddled in small groups or are being moved around the room. Some of the captives are flex-tied. Lying on the floor of the room are the bodies of several men who appear to have been executed.
The fighters speak in Russian, according to a translation of the video by Foundation for Defense of Democracies’ Boris Zilberman.
“They spoke pretty decent Russian … better than some of the folks that you can usually find on Kavkaz Center,” Zilberman said, referring to one of the propaganda arms of the Islamic Caucasus Emirate.
The fighters seem eager to proceed with the execution, while the cameraman is concerned about the angle he should use to film it.
“Come on, come on, what about this injured?” one of the fighters says.
“Should I film from the front or back?” the cameraman asks. He decides to film from the rear.
Seven men are lined up, kneeling on the ground. One of the fighters walks behind the men, and buttstrokes each of the men in the back of the head. A group of fighters then lines up and opens fire, killing the men.
“This is what happens to those that fight against Islam,” the fighter says to the leader. The leader then points to a man on the ground who appears to be still alive, and orders the men to shoot him again.