THE level of police security in the centre of London has been increased significantly following the bomb explosion. The most obvious signs are the armed police officers outside the House of Commons and roadblocks on all major routes into the city.
A spokeswoman at Scotland Yard refused to comment on the "operational procedures" implemented in the capital, but staff at all London Underground and British Rail train stations have been alerted to be "extra vigilant" for fear of further attacks.
An official at London Underground confirmed that staff, including train guards and drivers, had received specific briefings on procedures for dealing with unattended packages.
The scale of the police security operation will almost certainly affect the everyday quality of life in London as "stop and search" units patrol in the Square Mile and the City at eight specific entry points. These will be staffed by police officers 24 hours a day, but Scotland Yard would not say how long the measures would stay in force.
On the Isle of Dogs, scene of Friday's bombing, police have set up roadblocks and searches are continuing during the forensic investigation of the area surrounding South Quay station.