Editor's note: This report is based on a one-year investigation by CNN into air cargo security in light of a thwarted plot by al Qaeda in October 2010 to blow up cargo jets over the United States. CNN's Nic Robertson's report "Deadly Cargo" airs on CNN Presents, Saturday and Sunday February 18, 19 at 8 p.m. ET.
By Paul Cruickshank
In late October 2010 al Qaeda in the Arabian Penisula (AQAP) dropped off two “printer bombs” at UPS and FedEx offices in Yemen addressed to the United States.
They were amongst the most sophisticated devices ever put together by al Qaeda terrorists, according to officials.
The group’s chief bomb-maker Ibrahim al Asiri filled the printer cartridges of laser printers with PETN, a white powdery explosive which is difficult to detect. He connected this explosive to a timer he hid in the circuitry of the printer. The group’s aim was to blow up the deadly cargo in planes over the eastern seabord of the United States, but the packages were intercepted in the UK and Dubai after a tip from Saudi intelligence. If the bombs had detonated, they had the potential to bring down the planes they were travelling on, according to authorities.
British explosive expert Sidney Alford built a replica device for CNN to demonstrate its explosive potential. CNN has left out several critical steps from the video so as not to disclose how to assemble the bomb.