The gravity of the incident was heightened by the fact that Queen Elizabeth II was being flown back to Heathrow by the RAF on 10 March.
Due to the bomb-proof windows, none of the cabinet were hurt, though four other people received minor injuries, including two police officers.
In April 1992 the IRA exploded two bombs at the Baltic Exchange in the centre of London and killed three people, including a 15-year-old girl.
The IRA warning proved to be inadequate and added to the confusion as it mentioned the Stock Exchange, there it was reported in the media that insurance claims amounted to £800 million.
A British Airways airliner to Copenhagen used the runway two minutes before the attack was launched from the car park of the Forte Excelsior Hotel, about 400 meters (440 yd) away, at 5.57 pm.
In a statement issued later that day, the IRA stated their "positive and flexible" attitude to the peace process was "abiding and enduring".
Irish Taioseach Albert Reynolds dubbed the attacks as "political naive", regarding the presumed IRA goal of extracting more concessions.