U.S. Maj. Gen. William Caldwell said the military had been conducting numerous operations against al-Qaida in Iraq over the last six days and he believed that had led to reports that Abu Omar al-Baghdadi and Abu Ayyub al-Masri had been killed in fighting.
He said the confusion apparently stemmed from the killing of another senior al-Qaida leader and a close associate of al-Masri, Muharib Abdul-Latif al-Jubouri, who had been linked to several high-profile kidnappings of Americans and other foreigners.
The comments came after the Iraqi Interior Ministry said Thursday that al-Baghdadi had been killed and showed pictures of what it said was his body. On Tuesday, officials reported that al-Masri, had been killed by rivals north of Baghdad but the body has not been recovered.
Regarding al-Masri, Caldwell said "we in fact do not have in our possession nor do we know of anybody that has anybody or person at this time that we think is him."
"His overall status whether he is dead or alive is actually unknown to us at this point," he added.
He also said the death of al-Baghdadi, the head of the Islamic State of Iraq, an umbrella insurgent group that includes al-Qaida, also could not be confirmed.
"If that person even exists, again, we have nobody in our possession or know of anybody that does, alive or dead, that is going through any kind of testing or analysis at this point with respect to those two individuals," he said.
Caldwell said al-Jubouri was killed while trying to resist detention in an operation about six kilometers (four miles) west of the Taji air base north of Baghdad, and the body was initially identified by photos, then confirmed by DNA testing on Wednesday.
Caldwell said al-Jubouri was believed connected with the kidnapping of American reporter Jill Carroll, who was released, and Tom Fox, one of four men from the Chicago-based peace group Christian Peacemaker Teams who was found fatally shot in Baghdad on March 10, 2006.