A US official has warned that the Khorasan Group in Syria poses a "clear and present danger" to flights headed to Europe and the United States.
The Independent reports that the al-Qaeda cell in Syria has been researching and testing explosive devices that will pass undetected through airport security.
John Pistole, the Obama administration's most senior aviation security expert said that the stakes are real and the threats are high.
He said that he saw the Khorasan Group as being a very capable, determined enemy who was very much focused on getting somebody or something on a plane bound for Europe or the United States.
Earlier, a report had revealed that Syria-based wing of Al Qaeda, Khorasan, was developing concealable explosives that can be smuggled aboard airplanes.
Sources said that the group was seeking help from Al Qaeda bomb-makers to develop such explosives. They also said that fighters with western passports were being recruited as operatives to conduct attacks in their home countries, reported CBS News.
The threat had prompted America to tighten security for US-bound flights from foreign airports in July.
