U.S. officials believe al-Awlaki played an important role in the failed December 2009 underwearbombplot and also the thwarted October 2010 cargo bombplot.
Then on 6 May, US officials said they had and their allies had foiled a plot to bomb a US plane, involving a device that bore the "hallmarks" of the underwearbomb carried by Umar Farouk Abdulmutallab in 2009.