The measures were introduced by Owen Kelly , then the City of London Police commissioner , following the IRA bombing campaign in London in the 1980s and early 1990s including attacks within the City such as the 1992 Baltic Exchange and 1993 Bishopsgate attacks .
The measures were introduced following a massive IRA bombing campaign in the City in the early 1990s such as the 1992 Baltic Exchange bombing and the 1993 Bishopsgate bombing .