Armed US marshals on flights over new bomb fears
Armed US air marshals travelled on flights from Britain to America last week amid fears of attacks using "underpants" bombs following the discovery of a new sophisticated device in the Middle East.
American counter-terrorism officials sent the undercover officers to Europe, insisting on the extra cover, it has emerged.
Days earlier, a double agent inside al-Qa'ida smuggled one of the hi-tech bombs, which are designed to evade metal detectors and be hidden in underwear, into the hands of Western intelligence agencies.
The agent took the device "safely out of Yemen" where it was built by al-Qa'ida's master bomb-maker.
Explosives experts say it is more sophisticated than the bomb that almost brought down a transatlantic airliner to Detroit on Christmas Day in 2009.
There are fears that the bomb-maker, Ibrahim Hassan al-Asiri, has built other devices, including ones that can be surgically implanted.
John Brennan, the White House counter-terrorism adviser, said he could not rule out that other bombers were still at large. Every flight from Gatwick was carrying armed officers, according to one report.
Britain's Department for Transport refused to comment last night.
Hillary Clinton, the US Secretary of State, said the latest plot indicated that terrorists "keep trying to devise more and more perverse and terrible ways to kill innocent people". (© Daily Telegraph, London)