On the morning of July 7, 2005, a co-ordinated attack by suicide bombers on the London public transport system resulted in four explosions at densely packed civilian targets. Of the victims of these attacks, 194 were treated at the Royal London Hospital, where among the most severely injured an unusual pattern of injury was seen. Bone fragments from other victims (or possible the bomber) were found embedded as biological foreign bodies within the soft tissues of several patients. We present case reports of five of these patients, and discuss problems arising from the management of their injuries. Allogenic bony foreign bodies, rarely reported in the medical literature, present unusual problems in their management, in particular the risk of transmitting blood borne diseases, which should be anticipated and addressed in a hospital's major incident planning.