The drone strike in Yemen that killed Al Qaida chief Anwar al-Awlaki appears to have also killed the terror group's top Saudi bomb-maker, US officials said.
Intelligence indicated Ibrahim al-Asiri also died in the attack, the officials, who spoke anonymously because the death had not been officially confirmed, said.
Al-Asiri is the bomb-maker believed to have made the explosives used in the foiled Christmas Day airline attack in Detroit, Michigan, in 2009 and last year's attempted cargo plane bombing.
Al-Asiri's death would make the attack perhaps the most successful single drone strike yet.
The FBI pulled al-Asiri's fingerprint off the bomb hidden in the underwear of the Nigerian man accused of trying to blow up the plane over Detroit.
Authorities also believe he built the bombs that al Qaida slipped into printers and shipped to the US last year in a nearly catastrophic attack.
Along with al-Awlaki, the drone attack also killed Samir Khan, the editor of the al Qaida propaganda magazine Inspire.
Both Khan and al-Awlaki are US citizens. Al-Awlaki was the target of the attack.
Christopher Boucek, a scholar who studies Yemen and al Qaida, said al-Asiri was so important to the organisation that his death would "overshadow the news of al-Awlaki and Samir Khan".