FILE - A member of militias known as Hashid Shaabi stands next to a wall painted with the black flag commonly used by Islamic State militants, in the town of al-Alam, Iraq.
FILE - A member of militias known as Hashid Shaabi stands next to a wall painted with the black flag commonly used by Islamic State militants, in the town of al-Alam, Iraq.

Islamic State extremists posted online another gruesome video broadcasting the brutal killings of accused spies and alleged apostates. This time death by drowning, being blown up by a rocket propelled grenade or an explosive attached to the neck were added to the catalog of the group’s ways of slaughtering enemies.
The seven-minute-long video using underwater cameras to film a group of men being drowned in a swimming pool while trapped in a cage, is yet another one of the shock movies in a long line designed to grab attention, especially in the West. IS supporters weren’t slow to circulate stills from the gory video on social media outlets, notes Charlie Winter, an analyst with the London-based research organization the Quilliam Foundation.
“None of IS propaganda is intended for one discreet audience,” he said. "But clearly they wanted a local audience to understand the consequences of defecting. This was about threatening people who are thinking of breaking with them. But the group has also perfected the skill in getting as much utility out of each video release as possible.”
Raw terror

Different audiences take different things from IS videos. Political activists in the Middle East see the video as an object lesson in raw terror and the primary target audience being in territory controlled by IS. They say it conveys a savage warning to anyone thinking of breaking away from the group, including Sunni tribes who aligned with the so-called Islamic State last summer to help the extremists expand their self-declared caliphate across a swath of Iraq and Syria.
Experts and activists believe the seven-minute video accompanied only by an Arabic-language commentary, was shot near the Iraqi city of Mosul in Nineveh province.
At a time the terror army is suffering defeats in the battlefield, the video released Tuesday included a personal warning to an Iraqi police officer, Bassem Mohammed, who has been organizing former policemen in Nineveh Province to fight IS. He told The New York Times he knew eight of the 16 men killed and was related to some.
The video also was accompanied by a lengthy statement from the terror army’s chief spokesman, Abu Mohammed al-Adnani. In it he warns Sunnis that they can see for themselves the consequences of IS losing to Iraqi government-backed Shia militias. The militias have been accused in Iraq of driving out Sunnis from territory captured from the terror army and abuses have been documented and condemned by rights groups.
He says the terror army is giving a last opportunity to Sunni opponents and apostates. “We give them this last chance, not from a point of weakness but a point of strength. This time we won’t exempt anyone from the clemency,” citing in particular in the Jaghayfa tribe in Haditha, a western Iraq town 240 kilometers northwest of Baghdad, “who have repeatedly betrayed us and fought us.”
IS is offering a carrot-and-stick approach, says activist Amir Salamah. “Repent and you will be forgiven, don’t and we will kill you in terrible ways.”
Propaganda campaign

That has been the IS approach to the Shaitat tribe in eastern Syria. For the past year, IS has been running a propaganda campaign aimed at intimidating the tribe. Last July, Shaitat tribesmen rebelled against IS and killed 11 extremists. In retaliation IS slaughtered hundreds of men and boys over the age of 15. In a video of the massacre, the laughing killers ask one of their victims how he wants to die, but ignore his request to be shot and behead him instead.

Last autumn, the terror leaders formally forgave the tribe although insisted none of the tribesmen could assemble in large groups.
Since then they have posted several videos showing various Shaitat tribesmen repenting and blaming thieves and apostates for leading the tribe astray in the first place. Some tribesmen have continued to resist IS and have been killed.
Analyst Winter expects more gruesome videos in the coming days. He notes locals in Palmyra, the Syrian town recently captured by IS, which boasts major Roman-era ruins, have reported a series of beheadings. And activists have also said there were some executions recently in a castle on Lake Assad, a reservoir on the Euphrates near Raqqa. “They like dramatic settings for their videos,” Winter said.