U.S. officials say a CIA drone strike Monday targeted al-Qaida's second in command, Abu Yahia al-Libi, in Pakistan's tribal areas.
U.S. officials said they didn't yet know whether al-Libi was hit, but they were "optimistic."
A U.S. official said fewer than five people were hit in two days of strikes. U.S. officials said the outcome of the strikes was not yet clear.
The FBI was offering a $1 million reward for the Libyan-born fugitive, who had filmed numerous propaganda videos urging attacks on U.S. targets after he escaped a prison at Bagram Air Base in Afghanistan in 2005.
Al-Libi became al-Qaida's No. 2 when Egyptian born Ayman al-Zawahri took charge of al-Qaida after the death of Osama bin Laden last year.