Islamic State militants are hoping to weaponise bubonic plague to use against “unbelievers," it has been reported.
Documents found on a "laptop of doom" apparently belonging to an IS fighter seemed to show that the group were searching for the weapons of mass destruction.
Searches for chemical weapons included instructions on how to weaponise the bubonic plague, also know as the Black Death, which caused around 30 million deaths in the 14th century.
The laptop contained a 19-page document with the details, explaining that “the advantage of biological weapons is that they do not cost a lot of money, while the human casualties can be huge.”
It chillingly explains that it would be most effective to “use small grenades with the virus, and throw them in closed areas like metros, soccer stadiums, or entertainment centers” near air-conditioning.
The Great Plague (1664-1666) was the last major epidemic of the bubonic plague to occur in the UK
The laptop, reportedly belonging to a Tunisian man named Muhammed S Abu Ali, was recovered in a raid against IS by a moderate Syrian rebel group.
Two journalists writing for Foreign Policy Magazine, Harald Doornbos and Jenan Moussa, were able to “crack” the laptop, where they uncovered a "treasure trove" of 35,000 hidden folders, taking up 146 gigabytes of hard drive storage space.
The documents include "videos of Osama bin Laden, manuals on how to make bombs, instructions for stealing cars, and lessons on how to use disguises in order to avoid getting arrested while traveling from one jihadi hot spot to another," Foreign Policy reports.
They also revealed that Muhammed S was apparently learning how to build biological weapons, having studied chemistry and physics at a Tunisian university. His whereabouts are currently unknown.
Foreign Policy also claimed to have found a 26-page fatwa, or Islamic ruling, on the usage of weapons of mass destruction.
"If Muslims cannot defeat the kafir [unbelievers] in a different way, it is permissible to use weapons of mass destruction."
"Even if it kills all of them and wipes them and their descendants off the face of the Earth."
The journalists behind the report tried to see the funny side of the bleak news:
The news comes as Britain’s threat Level for International Terrorism increased to "severe" yesterday after an increase in Islamic State jihadist activity.
Highlighting the danger of extremists returning to Britain, Prime Minister David Cameron said the "scale of this threat is growing".
"It is becoming clear that there are some gaps in our armoury, and we need to strengthen them.
America's Centres for Disease Control and Prevention (CDC) highlights that as far back as the 14th century, armies have used plague in various fashions.
Although there is no evidence IS has acquired any biological weapons yet, fears were rising since the militant group seized a former chemical weapons silo in Iraq last month.
But experts stressed to Vice News that it is "incredibly hard to develop and put biological weapons to use."
Dan Trombly, an analyst at Caerus Associates specialising in armed conflict, told Vice that biological weapons are often "more trouble than they're worth."