Free Talk Live

In a further development which added to concern over the ease with which the explosive material used in the devices – Pentaerythritol tetranitrate, or PETN – can be passed through all kinds of airport security, Qatar Airways said the bomb found in Dubai had travelled on two separate passenger aircraft without being picked up. "There is no way of picking out PETN," said the British counter-terrorism official. "It is a continued vulnerability."