Experts in Germany said the bombs at East Midlands Airport and in Dubai contained at least 300g (10.58oz) of the powerful explosive PETN, as British Home Secretary Theresa May announced a review of all air freight security.
British explosives expert Sidney Alford told CNN last year that just 6g of PETN would be enough to punch a hole into a metal plate twice the thickness of an aircraft fuselage.
Prime Minister David Cameron, who chaired an hour-long meeting of the British Government’s emergency committee, Cobra, yesterday, said every possible step must be taken “to work with our partners in the Arab world to cut out the terrorist cancer that lurks in the Arabian Peninsula”.
May told MPs both bombs originated in Yemen and were believed to be the work of al-Qaida in the Arabian Peninsula (AQAP).
“The devices were probably intended to detonate mid-air and to destroy the cargo aircraft on which they were being transported,” she said. “Had the device detonated we assess it could have succeeded in bringing down the aircraft.”
While there was no information to suggest another attack of a similar type was imminent, the authorities were working “on the assumption that this organisation will wish to continue to find ways of also attacking targets further afield”, Mrs May said.
Announcing the security review, she said all flights containing unaccompanied freight from Somalia will be suspended in the wake of the terror plot.
The suspension, which will come into force from midnight, was a “precautionary measure” based on “possible contact between al-Qaida in Yemen and terrorist groups in Somalia, as well as concern about airport security in Mogadishu”, May said.
The bomb at East Midlands Airport was removed from a UPS aircraft by Leicestershire police officers shortly after 3.30am on Friday following a tip-off from Saudi intelligence. It had travelled through a UPS hub at Germany’s Cologne airport before being detected in Britain following the tip-off, officials said.
Yemeni security officials said the tip-off came from a leading al-Qaida militant who turned himself in to Saudi authorities last month. Jabir al-Fayfi told authorities about the plan by AQAP, the terror group’s affiliate in Yemen.
Norman Shanks, former head of security at airport operator BAA, said it was time to introduce “package by package” screening after it emerged one of the cargo plane bombs was transported on passenger aircraft before being found. Ryanair boss Michael O’Leary warned against over-reacting, saying he feared a new raft of “ludicrous” airport security measures.
Meanwhile, the FBI and Homeland Security Department in the US warned local officials across the country that packages from abroad with no return address and excessive postage required a second look.
An anti-terror probe was focusing on Saudi-born bomb-maker Ibrahim Hassan al-Asiri as the prime suspect for making the bombs. He is also believed to have been responsible for making the device involved in the failed Christmas Day bomb plot over Detroit last year.
US deputy national security adviser John Brennan said “it would be very imprudent . . . to presume that there are no others (packages) out there”.