A spokeswoman for the Corporation said the new police checkpoints that encircle the heart of the City had been devised primarily to prevent huge lorry and car bombs, which have twice devastated the City over a 12-month period. 'It was never meant as a solution for dealing with much smaller-scale devices,' she said.
The police said that the device, which was made safe with a controlled explosion, was found behind a hoarding on the south footway of Wormwood Street following a telephone call from a man with an Irish accent who used a recognised codeword. The hoardings surround the area of the City that bore the brunt of the Bishopsgate lorry bomb that exploded in April. Reconstruction work is still being carried out on buildings in the area.
Police said the device was small enough to have been concealed in a coat or bag. No one was injured and no property damaged. City of London police are conducting a joint investigation into the incident along with Scotland Yard's anti-terrorist branch.
The City Corporation is continuing to review its security policy and has recently completed a period of consultation which could pave the way for a public inquiry into the new measures. New legislation would be required to make them permanent.
There was widespread concern among City businessmen over security following two previous bomb attacks. On 24 April, a bomb concealed in a stolen lorry exploded in Bishopsgate, killing a news photographer, injuring dozens and causing millions of pounds of damage.
A year earlier, on 10 April, a huge car bomb packed with more than 100lb of high explosives went off outside the Baltic Exchange, killing three, including a 15-year-old girl, and injuring 91.
Motorists now entering the City are routinely stopped and searched at the permanent checkpoints. Roving units of armed police regularly set up temporary vehicle checkpoints inside the area. The Corporation is also advising City firms to install more security cameras.
One new security measure being considered is a paging device that would allow police to alert whole sections of the City to the presence of a suspected bomb with the single press of a button. The system would remove the need for police to rely on the less satisfactory method of using loud-hailers on the streets or telephoning a large number of individual companies to warn them to evacuate.