The young Yemeni woman arrested on suspicion of mailing powerful bombs to U.S. synagogues was released on bail Sunday, and a Yemeni official said authorities no longer believe she shipped the bombs.
Authorities arrested the woman after tracking the name and address used on the packages.
But after the woman was arrested, the shipping agent said she wasn't the one who signed the shipping documents, the official said.
The release means investigators no longer have any suspects in custody in a suspected al Qaeda plot that authorities believe was intended to take down cargo jetliners.
The Yemeni official, who spoke on condition of anonymity because of the ongoing investigation, said investigators now believe someone stole her identity and used it to mail the bombs.
Whoever mailed the bombs had used her name, address and telephone number, the official said.
The packages traveled on two passenger flights within the Middle East, a Qatar Airways spokesman said Sunday. The U.S. said the plot bears the hallmarks of al Qaeda's offshoot in Yemen and has vowed to destroy the group.
The woman, an engineering student whom colleagues say is not known to be involved in any political activity, was released on bail but cannot leave the country pending further questioning.
U.S. officials today pointed to a key al Qaeda figure as being the chief suspect in the attempted attack.
Intelligence officials say Ibrahim Hassan al-Asiri, who is suspected of packing explosives into the underwear of the Nigerian man accused of trying to blow up an airliner near Detroit last year, is believed to be behind the mail bombs.
Al-Asiri is one of the leaders of al Qaeda in the Arabian Peninsula, (AQAP), joined there by a U.S.-born preacher, Yemeni militants and former Saudi inmates of Guantanamo.
Officials say al-Asiri sent his own brother on a suicide mission against a top Saudi official. But that mission was unsuccessful.
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Yemeni officials said there were additional suspects believed to have used forged documents and ID cards. One member of Yemen's anti-terrorism unit said the other suspects had been tied to al Qaeda.
Yemeni and U.S. officials spoke on condition of anonymity to discuss the ongoing investigation unfolding on three continents.
It still was not clear whether the bombs, which officials said were wired to cell phones, timers and power supplies, could have been detonated remotely while the planes were in the air, or when the packages were halfway around the world in the U.S.
Al Qaeda in the Arabian Peninsula took responsibility for the failed bomb last Christmas that used PETN, an industrial explosive that was also in the mail bombs found Friday.
More on Terror Packages:
Security Gaps Plague Cargo Shipping
Explosives Found on Planes Amid U.S. Terror Probe
PETN Explosive a Favorite of Terrorists
More on Yemen:
Yemen: The Next Front Line Against al Qaeda
Yemen Eyed as Source of Suspicious Packages
C.I.A. Drones May Target Yemen Terrorists
Concern Over Yemen Terror
CIA: Al Qaeda in Yemen Now Biggest Threat
By Associated Press writers Ahmed Al-Haj and Adam Schreck. Matt Apuzzo, Adam Goldman and Kimberly Dozier in Washington, Raphael G. Satter and Gregory Katz in London, Hamza Hendawi in San'a, Yemen, and Carla K. Johnson and Karen Hawkins in Chicago contributed to this report