Activists studying the havoc, punishment and despair inflicted on the Syrian city of Raqqa by the Islamic State (Isis) militant group have documented some of their brutal torture techniques. Daesh (Isis) have carved out their self-proclaimed caliphate in Syria and Iraq making Raqqa their de-facto capital.

Since the takeover of the provincial city in the north of war-torn Syria Raqqa Is Being Slaughtered Silently (RBSS) has been smuggling information from the city to the outside world. The underground journalist-activists have seen their members killed whilst attempting to get the word out to the wider world about the plight of their countrymen.

The jihadists attempt to spread fear into the hearts of civilians by kidnapping activists, journalists, leaders, people of other religions, or anyone who disobeys their strict Islamic law. And the barbarity of the IS torture of its prisoners is only comparable to the executions that occur in the towns and cities that are ruled by the extremists.

One of the methods used to scare prisoners would be sending in a jihadist to a prisoners cell whilst carrying another prisoner's amputated head, promising the same fate.

"The ISIS prison wardens would speak continuously of the coming retribution. ISIS men would enter, place knives on our necks, and threaten to kill us. An ISIS member would occasionally enter carrying a prisoner's amputated head, promising the others a similar fate," stated Ahmed, an activist in the RBSS movement to the Atlantic Council.

The RBSS say that evidence that IS were torturing the population emerged after Dr Hussein Abu Rayyan, head of the Tel Abyad border crossing and member of the Ahrar al-Sham Islamic movement was killed in 2013. The forensic report revealed fractures in his neck and ribs, bullet wounds in his hands and legs, and an amputated ear.

Today in the streets of Raqqa, IS have erected steel cages filled with human skulls that are used to imprison women for one night who disobey their strict version of Sharia Law. RBSS say that the most oft-used torture technique is lashing used to elicit information and confessions from victims.

Another technique is called the 'shabeh' or 'ghost' method when the jihadist hangs the prisoner with hands tied behind their back with handcuffs, which are then used to suspend their bodies in the air. After days in this position the prisoner often loses his ability to move his hands, dislocates his joints, and could cause damage to his brachial plexus, resulting usually in permanent disability.

Isis militant Raqqa
Isis rules over large swathes of Syria and Iraq Reuters

They also use electric shock torture, which can lead to death, caused by damage to heart muscle or electric burns.

Women in Mosul have described one punishment called 'The Biter' which involves using an iron jaw on women who fail to abide by the IS dress code. First used in the Middle Ages the tool clips off pieces of flesh with one woman telling the Independent that: "the biting punishment is more painful than labour pains."

RBSS also documents 'The Flying Carpet', which is a metal board with hinges in the middle. The prisoner is tied to these hinges. It is then closed, causing a brutal bend in the spine that may lead to fractures.

Other techniques include 'The German chair' where the victims are strapped to a chair whose back is adjusted to cause extreme spinal damage and 'The Tyre' where victims are placed inside a large tyre rendering them immobile before they are beaten.

Isis video game 2
Isis militants are known for their brutal treatment of prisoners Islamic State propaganda image