FBI officials said Tuesday the Boston Marathon bombs that killed three and wounded 176 may have been fashioned out of pressure cookers packed with shards of metal, nails, ball bearings and other shrapnel-type material.
Following the announcement, media reports started showing up shedding light on pressure cooker bombs, which are made from a common kitchen appliance and seem to be a favorite within in counterterrorism circles.
In 2004, the Department of Homeland Security issued an alert to federal and state security officials, calling it “A technique commonly taught in Afghan terrorist training camps is the use/conversion of pressure cookers into IEDs."
A pressure cooker is an airtight utensil for quick cooking or preserving foods by means of high-temperature steam under pressure, like a rice cooker. According DHS, these bombs are typically made by placing TNT or other explosives in a pressure cooker and attaching a blasting cap at the top of the pressure cooker.
Instructions to make bombs out of pressure cookers were published two years ago in Inspire, an online magazine tied to al-Qaeda and the late U.S.-born cleric Anwar al-Awlaki, USA Today reported Tuesday.
Investigators said Tuesday they were analyzing the explosive devices at an FBI lab in Virginia, but did not say what explosive material set off the bomb. Reuters reporter gun powder may have been used.
Boston doctors treating the wounded said victims were maimed by what looked like fragments of medal and plastic as well as ball bearings or BBs. Doctors also said they removed an array of sharp objects from the victims, including nails from one little girl’s body.