London car bombing part of campaign

LONDON - The detonation of a car bomb on a street in London on Sunday was what anti-terrorist officers had been fearing for months.

Ever since a member of a dissident Irish republican terrorist group - almost certainly the Real IRA - fired a rocket-propelled grenade into the side of the headquarters of MI6 on the banks of the River Thames last September, Scotland Yard and MI5 have been on high alert for the next assault.

Last November the Met's anti-terrorist branch warned that terrorists opposed to the peace talks in Northern Ireland could be planning an attack on mainland Britain with the sort of vehicle bomb that killed 29 people in Omagh in 1998. A senior officer said at the time: "The most worrying form of attack, and it brings back the spectre of Omagh, is a large vehicle bomb in a city centre with all the butchery that enfolds."

Until now the Real IRA appears to have been content to use low-risk terror devices at high-profile targets to maximise publicity and disruption. It is thought to be behind a bomb that was detonated on Hammersmith Bridge, west London, last Juned minor damage but substantial disruption. Six weeks later a device containing a kg of TNT explosive and a kitchen clock timer was found on a railway line at Ealing, west London. This was followed by the rocket attack on the MI6 building.

Security sources have confirmed there is at least one Real IRA active service unit operating in London and the Met's anti-terrorist branch believes there are "tens" of terrorists on the mainland. The taxi bomb also gives credence to fears that the Real IRA has successfully replicated the IRA's highly disciplined "active service units." The units, comprising just a handful of members living apparently ordinary lives, were designed to allow the IRA to leave operatives in London and elsewhere for long periods without exposing themselves to capture.

It has been many years since a republican grouping defined any broadcasting organisation as a "legitimate target" and launched a major attack on it. The unusual nature of this bombing strongly suggests that the Real IRA took particular exception to a BBC Panorama programme on the organisation and the Omagh bombing.

- HERALD CORRESPONDENTS