Investigators are leaning in the direction that the same person or persons who crafted the Christmas Day underwear bomb were behind the PETN-based devices hidden in packages sent from Yemen, a U.S. government official told CNN.
"The thinking is it's the same person or group of people that built the underwear bomb, because of the way it's put together. But this one is about four times as powerful," the official told CNN.
The official added that U.S. authorities now are endorsing British Prime Minister David Cameron's position that the explosives were designed to take down an airplane.
On Friday, U.S. officials publicly said they have not taken a position on whether cargo or passenger planes were the ultimate targets, or the Chicago syanagogues where the explosive-laden packages were addressed.