Pressure cooker bombs are relatively easy to construct. Most of the materials required can be easily obtained. The bomb can be triggered using a simple electronic device such as a digital watch, garage door opener, cell phone, pager, kitchen timer, or alarm clock. The power of the explosion depends on the size of the pressure cooker and the amount and type of explosives used. Similar to a pipe bomb, the containment provided by the pressure cooker means that the energy from the explosion is confined until the pressure cooker itself explodes. This in turn creates a relatively large explosion using low explosives and generating potentially lethal fragmentation.
Step-by-step instructions for making pressure cooker bombs were published in an article titled "Make a Bomb in the Kitchen of Your Mom" in the Al-Qaeda-linked Inspire magazine in the summer of 2010, by "The AQ chef". The article describes the technique as a simple way to make a highly effective bomb. Analysts believe the work was the brainchild of Anwar al-Awlaki, and edited by him and by Samir Khan. Inspire's goal is to encourage "lone wolf" Jihadis to attack what they view as the enemies of Jihad, including the United States and its allies. 's vehicle in New York’s Times Square bombing Several Islamic radical terrorist attempts in the 2010s involved pressure cooker bombs. The unsuccessful Times Square car bombing attempt in May 2010, in New York City, included a pressure cooker bomb which failed to detonate. The bomb-maker, Faisal Shahzad, was sentenced to life in prison. In the December 2010 Stockholm bombings, a suicide bomber with extreme views on Islam set up a pressure cooker bomb, which failed to detonate. In July 2011, Naser Jason Abdo, a U.S. Army private at Fort Hood, Texas, who took pressure cooker bomb-making tips from the Al-Qaeda magazine article, was arrested for planning to blow up a restaurant frequented by U.S. soldiers. Two pressure cookers and bomb-making materials were found in his hotel room. He was sentenced to life in prison. In Pakistan, in March 2010, six employees of World Vision International were killed by a remotely detonated pressure cooker bomb. In October 2012, French police found a makeshift pressure cooker with bomb-making materials near Paris as part of an investigation into an attack on a kosher grocery store. Two pressure cooker bombs were used in the Boston Marathon bombings in April 2013. The pressure cookers were filled with nails, ball bearings, and black powder. Initially, it was believed the devices were triggered by kitchen-type egg timers, however, subsequent evidence indicated a remote device was used to trigger the bombs. One of the bombers, Dzhokhar Tsarnaev, told investigators that he learned the technique from an article in Inspire magazine. On Canada Day 2013, pressure cooker bombs failed to explode at the Parliament Building in Victoria, British Columbia. On May 19, 2016, passengers on a bus in Wrocław, Poland, alerted the driver to a suspicious package. The driver removed the package from the bus. Shortly later it exploded with no fatalities but did injure one woman slightly. Authorities believed it was a three liter pressure cooker packed with nails and nitrate explosive. On September 17, 2016, an explosion occurred in Lower Manhattan, New York, wounding 29 civilians. The origin of the explosion was found to be a pressure cooker bomb. At least one other bomb was found unexploded. A suspect for that explosion and others in New Jersey, Ahmad Khan Rahami, was captured two days later. Both the 2010 Stockholm bombings and the foiled 2016 Sweden terrorism plot involved pressure-cooker bombs.
