An improvised explosive device detonated at the Parsons Green subway station in London during the morning rush hour commute on Sept. 15. The device, which in images from the scene appears to be a white bucket concealed in a grocery bag, is likely the work of an amateur bombmaker.
Though the device's timer was set to detonate during rush hour, the charge failed to achieve its maximum impact. Rather than inflicting the type of injuries usually associated with a large explosive device, the bomb injured 22 people and caused additional flash wounds and burns. Images of the device also show that the perpetrator used Christmas lights to detonate the main charge — a design that has appeared in bombmaking instructions published in al Qaeda in the Arabian Peninsula's Inspire magazine. This suggests that an aspirational jihadist may have carried out the Parsons Green attack.
It is also notable that the device was timer-detonated, a tactic typically used to conduct simultaneous or serial attacks. Coupled with the fact that Inspire magazine's last issue called for grassroots militants to carry out attacks on trains, train stations and rail lines, this indicates that additional attacks should be expected.
The bombmaker is still at large and could remain a threat if he or she is able to increase the efficacy of the bomb design. London has already suffered vehicular and knife attacks by terrorists earlier this year. Nevertheless, given the surveillance and forensics available to London authorities, the perpetrator will likely be detained quickly.
Editor's Note: This report was produced in collaboration with Threat Lens, Stratfor's unique protective intelligence product. Designed with corporate security leaders in mind, Threat Lens enables industry professionals to anticipate, identify, measure and mitigate emerging threats to people and assets around the world.