The Islamic State, the organization that has employed brutal methods to take over large swaths of territory in Iraq and Syria, is also trying to develop biological weapons , Foreign Policy reported, citing information found on a laptop computer seized from an IS operative.

Foreign Policy
obtained the computer from a moderate Syrian rebel group who seized the laptop in the Idlib province from an Islamic State hideout whose fighters had fled.

The laptop, belonging to a Tunisian operative of the Islamic State, named Muhammed S., with a background in chemistry and physics, included a 19-page document on developing biological weapons and weaponizing the bubonic plague.

"The advantage of biological weapons is that they do not cost a lot of money, while the human casualties can be huge," the document says in Arabic, according to Foreign Policy.

Among the files on the seized computer is also a ruling from a Saudi cleric justifying the use of weapons of mass destruction. "If Muslims cannot defeat the 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."