A Western official confirmed to United Press International that al-Libi was killed along with a dozen others in a midnight strike Monday in the Pakistani tribal agency of North Waziristan.
The death was earlier reported by one of the webmasters of an al-Qaida-affiliated password-protected online forum, Ekhlaas.org.
The official said al-Libi was one of "the top five or six" al-Qaida leaders, involved in "planning, recruiting (for) and directing" the group's operations in Afghanistan -- "but not just in Afghanistan."
Seth Jones, an expert at the RAND Corp., a think tank with historic ties to the U.S. military, told UPI that al-Libi's role was "primarily" directing operations against coalition and Afghan forces in Afghanistan. Jones added that he had "recently taken on a higher public profile," culminating in a video last November featuring al-Qaida deputy leader Ayman al-Zawahiri, in which al-Libi announced the merging of his Libyan Islamic Fighting Group with al-Qaida.
"This is someone the Afghans and the United States have wanted for some time," he said.
Intelcenter, a contractor for the U.S. government that tracks al-Qaida media releases, said in a statement that audio of al-Libi had featured in that November video and others last year, but that the last video of him was from April 2007 -- an interview conducted by al-Qaida's media arm as-Sahab.
In a statement the firm said it expected a video eulogizing al-Libi, from Zawahiri or another al-Qaida leader, to be released soon.
Jones said the death would be "a significant blow (to al-Qaida) in the short term" but that the group had a pool of experienced fighters it could draw from to replace him.
"Targeting (individuals) is not sufficient," he said, "as long as (al-Qaida) continues to have safe territory" in the Pakistani tribal areas.
Shaun Waterman, UPI Homeland and National Security Editor
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