Last suspects in failed bombings nabbed
(AP)
Updated: 2005-07-30 08:40

Peter Clarke, head of Scotland Yard's anti-terrorist branch, sounded a cautionary note as he announced the arrests.

"Despite the progress that has been made with the investigation, we must not be complacent," Clarke warned. "The threat remains, and is very real."

Authorities have been looking for a link between the failed July 21 attacks and the July 7 suicide bombings, which killed 56 people, including the four bombers. Three of the suicide attackers had links to Pakistan.

They have a working hypothesis that the cells did not know each other, but were connected by a more senior operative higher up an organizational chain, said a counterterrorism official, who spoke on condition of anonymity because investigations are ongoing.

Authorities also are theorizing the plot may be linked back to Pakistan and the al-Qaida organization there. However, "we are not there yet in terms of proving it," the official said.

The official said the newly detained individuals are being questioned, and authorities haven't ruled out that additional cells may be on the loose. It's also not yet clear precisely why a team of young men of mostly Pakistani descent and a second team of African men were put together.

A British police official said of any potential cell links: "Yes, it is possible they may not have been known to each other but had a conduit working between them for someone else."

On the links back to Pakistan and al-Qaida, the official said it was too early to make that connection and noted police have 20 people in custody for questioning, with the inquiry expected to last several months. The official was not authorized to give his name.