Police were alerted shortly before 3pm yesterday by a caller who used a recognised code word. No group has claimed responsibility but it is being treated as the work of the IRA.
Det Supt John White of the City of London police said a bomb small enough to fit inside a pocket had been recovered by hoardings screening building work in Wormwood Street. It was made safe.
He could not confirm whether the device was similar to the incendiaries used in the terrorist attack on Bournemouth, Dorset, earlier this month.