<p><br /> Police say the US-bound package discovered on a plane in Dubai contained explosives and an electrical circuit linked to a mobile phone SIM card.<br /> </p><p><br /> The device was also said to have been prepared in a "professional manner" and bore the hallmarks of terror groups such as al Qaida.<br /> </p><p><br /> The explosive material PETN, or pentaerythritol trinitrate, was used. This is the same chemical found after the failed attempt to blow up a plane over Detroit last Christmas.<br /> </p><p><br /> A major international terror alert was launched after security staff found printer cartridges with wires attached at cargo hubs at East Midlands Airport in the UK and Dubai on Friday.<br /> </p><p><br /> The packages were addressed to synagogues in Chicago, and were on Chicago-bound cargo planes that had set off from Yemen in the Middle East.<br /> </p><p><br /> The bomb also contained lead azide, an explosive compound which can be used in detonators.<br /> </p><p><br /> Police say they were tipped off by a call from abroad. The phone call warned of the possibility of an explosive device hidden in postal packages onboard the FedEx flight from Yemen.<br /> </p><p><br /> US President Barack Obama said on Friday night he was dealing with a "credible terrorist threat".<br /> </p><p><br /> Home Secretary Theresa May confirmed the package at East Midlands did contain explosive material, but said it was not yet clear whether it was a "viable explosive device".<br /> </p><p><br /> Forensic experts were examining the finds, which have been linked to al Qaida in the Arabian Peninsula, based in Yemen.<br /> </p><p><br /> Cobra, the UK Government's emergency planning committee, was meeting to discuss the situation but David Cameron, who is at his Chequers country residence, was not due to attend or take part.<br /> </p><p><br /> Downing Street said the Prime Minister had spoken to the Home Secretary last night, and was being kept up to date with the situation.<br /> </p>
