Washington: The United States, in September, intercepted two parcels which came from Yemen and were thought to be a dry run for the package bomb plot, a US official said on Monday, as Western governments tightened freight security.
Intelligence officials believe the tracking of the shipments may have been used to plan the route and timing for two parcel bombs discovered on Friday on US-bound planes.
"That was one scenario that was considered," said an official who spoke to The New York Times on condition of anonymity.
The dry run involved a box of household goods including books, religious literature and a computer disk, but no explosives, being shipped from Yemen to Chicago.
Related story: Test parcels intercepted in September
Bomb found in Dubai travelled on passenger flights
ABC has reported that officials believe the earlier flight might have been used to track how long it took and whether there would be any problems for the package getting through the system.
Just last Thursday, packages, addressed to Jewish institutions in Chicago and containing the lethal explosive PETN, hidden in ink toner cartridges, were uncovered in Britain and Dubai, on cargo planes bound for the United States.
However, now it has emerged that the US linked the packages several weeks ago to Al Qaida in the Arabian Peninsula, according to a US official.
"The boxes were stopped in transit and searched," the official said. "At the time, people obviously took notice and, knowing of the terrorist group's interest in aviation, considered the possibility that AQAP might be exploring the logistics of the cargo system," the official added. "When we learned of last week's serious threat, people recalled the incident and factored it into our government's very prompt response."
ABC News, which broke the news of the dry run, said it had been told by senior officials that ever since the September discovery, US intelligence agencies had specific concerns about AQAP's interest in Chicago.
New restrictions on air freight
Meanwhile, Western governments have imposed new restrictions on freight in the wake of the plot, as Yemen scrambles to contain the fallout by announcing exceptional security measures on all freight leaving Yemeni airports.
A team of US experts is heading to Yemen to provide screening, training and equipment to examine cargo shipments at the main international airport in the capital Sana’a.
Qatar Airways has revealed that one of the packages had been flown from Sana’a to Doha and then on to Dubai on one of its passenger aircraft, raising even more concern in Western capitals.
Britain announced on Monday that it was suspending all unaccompanied air cargo from war-torn Somalia, extending an earlier ban on freight from Yemen.
Germany said it was banning all flights from Yemen, after the discovery of the bomb at East Midlands airport in Britain, which passed through the German city of Cologne.
British Prime Minister David Cameron has vowed to work with partners in the Middle East to "cut out the terrorist cancer that lurks in the Arabian Peninsula."
"The fact that the device was being carried from Yemen to the UAE to Germany to Britain en route to America shows the interest of the whole world in coming together to deal with this," Cameron told parliament.
The Dubai bomb was composed of a highly explosive combination of PETN and lead azide, hidden inside a computer printer with a circuit board and mobile phone SIM card attached, security officials said.
The British Home Secretary, Theresa May, has announced a ban on passengers carrying toner cartridges larger than 500 grammes in their hand luggage.
The BBC reported that the bombs had been discovered following a tip-off from a former Al Qaida militant who handed himself in to Yemeni authorities two weeks ago.
Jabr Al Faifi is a former Guantanamo detainee who was sent back to Saudi Arabia for rehabilitation in 2006, but later escaped to Yemen and rejoined Al Qaida.
Saudi bomber is key suspect
An alleged Saudi bomb maker, Ebrahim Hassan Al Asiri, has emerged as a key suspect in the bomb plot.
"Al Asiri's past activities and explosives' experience make him a leading suspect," a US counter-terrorism official said on condition of anonymity.
The militant, who is thought to be hiding out in Yemen, was already wanted for designing the "underwear" bomb, worn by the young Nigerian accused of trying to bring down a packed airliner as it landed in Detroit on Christmas Day 2009.
Months earlier, Asiri sent his 23-year-old younger brother on a suicide mission, with 100 grammes of PETN under his white Saudi robe, to kill Saudi intelligence chief Prince Mohammad Bin Nayef, who was wounded but survived.
