Six more arrests in the UK. "The arrests bring to 18 the number of people held in connection to the July 21 attacks, including the four suspected would-be bombers." Here is the AP story on the same. And, according the London Times:

A third Islamist terror cell is planning multiple suicide bomb attacks against Tube trains and other “soft” targets in central London, security sources have revealed.

Intelligence about a cell with access to explosives and plans to unleash a “third wave” of attacks was the trigger for last Thursday’s unprecedented security exercise. The operation saw 6,000 police, many armed, patrolling across London.

Senior police officers say that there was “specific” intelligence from several sources that an attack was planned for that day. The disclosure contradicts official statements by Scotland Yard that Thursday’s security exercise — the biggest since the second world war — was simply a precaution aimed at reassuring the public.