WASHINGTON, Jan 10 (Reuters) - The succession of Al Qaeda leader Ayman al-Zawahiri, who was believed to have been killed in a U.S. raid last year, remains unclear, a U.S. intelligence official said on Tuesday.
"The question for Al Qaeda, that it has not answered for itself, is who follows (Zawahiri)," Christine Abizaid, director of the U.S. National Counterterrorism Center, said in an event organized by the Washington Institute when asked about Al Qaeda's "center of gravity" after Zawahiri's death.
Al Qaeda has not named a successor.
Saif al-Adel, a mysterious, low-key former Egyptian special forces officer who is a high-ranking member of Al Qaeda, is seen by experts as the top contender.
The United States is offering a reward of up to $10 million for information leading to his arrest.