A telephone text message claiming to be from al-Qaida's media arm confirmed al-Quso was killed in the strike.
He was also one of the most senior al-Qaida leaders publicly linked to the 2009 Christmas airliner attack and allegedly met in Yemen with the suspected Nigerian bomber, Umar Farouk Abdulmutallab, before the Nigerian left to execute his failed attack over Detroit with a bomb concealed in his underwear.
In December 2010, al-Quso was designated a global terrorist by the State Department, an indication that his role in al-Qaida's Yemen offshoot, al-Qaida in the Arabian Peninsula, had grown more prominent.
Local Yemeni official Abu Bakr bin Farid and the Yemeni Embassy in Washington confirmed al-Quso was killed in Rafd, a remote mountain valley in Shabwa. It is the area where many al-Qaida leaders are believed to have taken cover, including the U.S.-born cleric Anwar al-Awlaki, who was killed in a U.S. airstrike last year.
Al-Quso's association with al-Qaida dates back more than a decade, when he met with Osama bin Laden in Afghanistan. Bin Laden allegedly told him to "eliminate the infidels from the Arabian Peninsula."
From there, al-Quso rose through the ranks. He was assigned in Aden to videotape the bombing of the USS Cole but fell asleep. Despite the lapse, he was declared the regional leader in Aden. He was also believed to have played a prominent role in al-Qaida's attack and the capture last year of Zinjibar.
AP Intelligence Writer Kimberly Dozier in Washington contributed to this report.
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