Sunday, July 31 2005 15:39 Hrs (IST) - World Time -

London: A third Islamists terror cell is planning multiple suicide bomb attacks on Tube trains and other 'soft' targets in central London, according to intelligence sources.

Intelligence about a cell with access to explosives and which plans to unleash a "third wave" of attacks was the trigger for last Thursday's unprecedented security exercise- the biggest since the second world war- in London, which saw 6,000 police, many armed, patrolling across the city, the Sunday Times said today (July 31, 2005).

The members of the third cell were said to be independent of the July 7 and July 21 terrorists but have "associations" with some of the suspects who have been arrested in connection with the July 21 attacks.

Senior police officers said that there was "specific" intelligence from several sources that an attack was planned for that day. The disclosure contradicted official statements by Scotland Yard that Thursday's security exercise was simply a precaution aimed at reassuring the public.

According to Sunday Observer, sweeping new security measures are to be introduced on Britain's road and rail networks this week, including highway patrol officers on the M25 who will check bridges for bombs.

Senior officers are particularly concerned there could be a third attack on Thursday, two weeks after the last attempt. The revelation comes as Osman, one of the suspects arrested in Italy, claimed that Muktar Said- Ibrahim, the bus bomber detained on in London on Friday, led the July 21 bombings, which "were a statement about the war in Iraq."