U.S. and allied officials are increasingly concerned that doctors working with al-Qaida's Yemen-based affiliate will implant bombs inside living militants in order to try to circumvent airport security measures and bring down aircraft, Reuters reported.
A CIA drone attack earlier this year killed a Yemeni doctor who had devised medical procedures to surgically plant explosive devices in humans, Reuters said, but the expert bomb-maker who invented the tactic is still at large.
Two attacks in 2009 -- including a failed plot to blow up a Detroit-bound plane on Christmas Day -- involved explosives sewn into the bomber's underwear. Authorities subsequently became concerned that militants would begin concealing explosives inside their body cavities, which would be harder to detect by airport X-ray machines.
Many Western airports installed unpopular body scanners in response to the threat.