The failure of an explosive device aboard an international flight landing in Detroit has U.S. officials scrambling to assess the potential new threat from a mixture that evaded detection.
Law enforcement officials say they want to figure out exactly how the device, consisting of powder and a liquid, was made and how much of a threat it may be.
Law enforcement officials said they had no preholiday intelligence about this type of attack.
In 2006, investigators in London uncovered a plot to use liquid-based explosives to blow up airliners.
The case prompted new restrictions and investigators are trying to determine whether the rules need to be tightened again.
Officials said the man appeared badly burned on his legs, indicating the explosive was strapped there.
The Airbus 330 carried 278 passengers and a crew of 11.