A secretive group called Task Force 20 spearheaded the assault on the convoy. The covert force specializes in tracking and targeting Iraqi officials based on intelligence from the CIA and other sources, defense officials said. Made up mostly of Army soldiers, Task Force 20 has targeted Hussein and others since before the war began.
The attack also involved other, unidentified military units, but Capt. Michael Calvert said the 3rd Armored Cavalry Regiment, responsible for a vast area of western Iraq stretching to the Jordanian and Syrian borders, did not play a role.
Abid Hamid Mahmud Tikriti, 46, considered by U.S. forces the fourth-most-wanted figure after Hussein and his sons, reportedly told U.S. interrogators after his capture this month that Hussein and his sons survived the war, but intelligence officials said they could not confirm the statement.
It was not clear if the general, who was Hussein's personal secretary, provided the tip that prompted Wednesday's attack.
Iraqis have expressed skepticism that Hussein is dead or that his secretary, whom several people described as "Saddam's shadow" would give his U.S. interrogators precise information on Hussein's whereabouts.
Rumors abound as to where Hussein may be. One Baghdad newspaper reported last week that the former president had been sighted driving a Pajero taxi around Baghdad, wearing a beard, glasses and an ankle-length traditional Arab robe.
Members of the Senate Intelligence Committee, usually apprised of developments in the search for Hussein, had not been briefed on the attack or the identity of anyone in the convoy.
In Baghdad on Monday, Lugar, Biden and Hagel predicted the U.S. presence in Iraq could last as long as five years. Lugar, chairman of the Senate Foreign Relations Committee, and Biden, the committee's ranking Democrat, told reporters that Bush must explain to the American public that the mission in Iraq is a long-term operation.
"There now needs to be real truth telling by the president and by each of us," Lugar said.
"We have not fully informed them of just what an undertaking this is," Biden said, adding that the cost would outstrip the revenue from Iraq's oil industry.
Staff writers Patrick J. McDonnell and Alissa J. Rubin in Baghdad and Bob Drogin and Sonni Efron in Washington contributed to this report.