Series of explosions led Yard to issue warnings

Over the last couple of months, police anti-terrorist officers have repeatedly warned of possible attacks in London by IRA splinter groups, particularly the Real IRA.

Over the last couple of months, police anti-terrorist officers have repeatedly warned of possible attacks in London by IRA splinter groups, particularly the Real IRA.

The first sign that the dissident republican group was moving its attention to the capital came on 1 June when a bomb exploded on Hammersmith Bridge, causing only minimal damage but substantial disruption to traffic and temporary closure of the bridge.

Six weeks later another device was found on a railway line at Ealing, and last month false bomb threats were made against three London bridges, all of which caused massive disruption to commuters.

Since the beginning of September, teams of officers have been keeping a round-the-clock guard on the main Thames river crossings, all of which are considered prime targets for groups determined to halt the peace process.

Although the Republican dissidents have launched a number of high-profile attacks in Northern Ireland, most notably the Omagh bombing, an attack on the MI6 building ranks asa major strike at the heart ofthe British establishment, ona par with the IRA mortar bomb raid on Downing Street. Mortar bombs were also used by the IRA to attack Heathrow airport in 1994

After the Hammersmith and Ealing attacks in the summer, a police source warned: "We have to accept the very real possibility that there's a team operating here in Britain." He added that the bombs were likely to continue and the campaign could move to large devices.