Large parts of London were cordoned off after the bombs, including University College Hospital, near Warren Street, where armed police reportedly chased a man - thought to be a bomber - into the building.
Soon afterwards, an internal memo was circulated among hospital staff asking them to be on the alert for a black or Asian man, 6ft 2ins in height, wearing a blue top with a hole in the back with wires protruding from it.
A press spokesman for the hospital confirmed that armed officers were inside. The incident is continuing.
It's the last sentence that most worries me... For how long???