The four London incidents involving detonators or failed explosions now appear to be concluded, with police requesting the public to return to normal activity. Casualties are reported to be very light. Three tube lines are still closed.
In a fifth incident, BBC News 24 TV showed pictures of police with automatic weapons arresting a man outside the Ministry of Defence in Whitehall.
Update (17.20 BST): The situation at UCH seems to be resolving itself, with patients being allowed to leave. Press are still being kept outside, however.
BBC News 24 is no longer showing the film of the man being arrested at gunpoint outside the MOD. The only footage of the arrest currently being shown is of the man lying prostrate on the pavement under police guard.
Five tube lines remain closed.
20.20 BST: Police cordons are still being maintained in large areas of the city.