"We do not have intelligence that he is and has been specifically in Tikrit," said Maj. Josslyn Aberle, spokeswoman for the 4th Infantry Division, which controls a large swathe of the country's north. "Because if we did, we would have the capability to act on it.
However, Aberle said there has been intelligence that former regime members, possibly even Saddam, had traveled through the area.
Aberle's comments contradicted those of Maj. Troy Smith, a deputy brigade commander, who on Monday told reporters the military has "clear indication" Saddam was recently in Tikrit.
Smith said the ousted leader was believed to wield a strong influence in the anti-American insurgency in Tikrit and that "he could be here right now."
Tikrit lies in the Sunni triangle area, which has produced the majority of the attacks against U.S. troops.
In other developments:
In Tuesday's attack, a car rushed at the embassy in the mid-afternoon and exploded, witnesses said. A concrete security barrier absorbed most of the blast, about 500 yards from the embassy, U.S. officials said.
Three embassy employees were slightly hurt, said Osman Paksut, Turkey's ambassador to Baghdad, interviewed on Turkey's private NTV television channel.
Col. Peter Mansoor of the U.S. 1st Armored Division said the vehicle's driver was killed. However, Iraqi witnesses said a second person also died and more than a dozen were injured.
About 50 people gathered behind the Turkish Embassy after the bombing, chanting pro-Saddam Hussein slogans and waving Iraqi banknotes with the ousted leader's picture. Police detained several of them.
Mansoor said an investigation by the FBI and Iraqi police had begun.
Tuesday's blast was the eighth suicide or vehicle bombing since early August, most targeting facilities of the U.S. administration or of Iraqis and other nations helping the occupation. The blasts have killed scores of people, and U.S. and Iraqi authorities have yet to determine who is behind any of them.
The latest attack came amid widespread Iraqi opposition — even from the U.S.-appointed Governing Concil — to the prospect of neighboring Turkey deploying troops on Iraqi soil. Many Iraqis fear Turkey seeks to dominate or grab territory in their country or that the deployment will cause friction with Kurds in northern Iraq.
But the United States strongly backs the Turkish deployment, part of what it hopes will be a larger influx of international troops to help U.S. soldiers in the struggle to bring order to Iraq. The Turks would be the first major contingent from a Muslim country.
White House spokesman Scott McClellan said the bombing showed that "the more progress we make, the more desperate the holdouts of the former regime and the foreign terrorists become."
Asked if he thought the bombing was related to the issue of Turkish peacekeepers, Mansoor said: "I think it has everything to do with that."
On Tuesday, radical Shiite Muslim cleric Muqtada al-Sadr said there would be no difference between Turkish soldiers and members of the U.S.-led force, which he wants to leave the country.
In the holy city of Karbala, rival Shiite Muslim factions clashed overnight, and several people were killed or injured, witnesses said. Iraqi police surrounded the offices of one of the faction leaders.
The clash appeared to be part of a power struggle in the majority Shiite community between forces of al-Sadr, a firebrand cleric and a strong opponent of the U.S. military occupation, and followers of religious leaders who have taken a more moderate stand toward the Americans.
Residents said up to 10 people were killed and more than a dozen wounded. Al-Sadr's staff put the casualty figure at one dead and three injured. Police refused to talk to journalists, and the atmosphere in the city, 50 miles southeast of Baghdad, was tense.