He said the man was "probably" the one chosen to succeed Zarqawi, the al-Qaida leader in Iraq who was killed in a U.S. air strike last week.
An Islamic militant Web site said Zarqawi's replacement was a man named Abu Hamza al-Muhajir. But his name was not familiar to U.S. and Iraqi officials.
"As we continue looking at the al-Qaida network there is no question that it is in some kind of disarray and disorganization at this point," Caldwell said.
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