Al-Qaeda Bomb-Making Suggestion: 'Pressurized cooker is the most effective method.'
The Boston Herald reported that federal investigators have determined that the Boston Marathon bombing was conducted using "kitchen pressure cookers packed with explosives, nails and other lethal shrapnel."
The inaugural issue of al-Qaeda's online screed Inspire, Summer 2010, included the instructional essay, "Make a bomb in the kitchen of your Mom." From p. 40:
The pressurized cooker is the most effective method. Glue the shrapnel to the inside of the pressurized cooker then fill in the cooker with the inflammable material. Insert the prepared lamp into the inflammable material gently in order not to break the filament of the lamp. Then have the wires sticking out of the hole in the lid of the cooker. Wrap some tape around the hole to seal any openings and connect the wires to the electric source in the same way as we did with the iron pipe.