MI5 Chief Warns Of Unprecedented, Growing Terror Threat

The head of the U.K.'s domestic security agency says the nation faces an unprecedented terror threat from a growing pool of Islamist extremists who can quickly plan and implement attacks.

The head of MI5, Andrew Parker, made his remarks Tuesday at his annual "state of the union" assessment of the threat facing the nation, as cited by the Independent (U.K.).

Parker said he has never seen such a high tempo of attempted and successful bombings, shootings and stabbings in his 34...