The extremely graphic photographs were distributed on CD-ROM in Baghdad, where many news wire services have reporters stationed. The pictures later were distributed to other news outlets.

Reporters who saw the photos of the bodies said they definitely were those of Uday and Qusay Hussein (search). One of the photos showed Uday with a thick beard and severely bruised face.

The pictures show the men from the chest up -- one on bloody white sheets and the other in what appears to be a body bag. The faces are caked with blood, the eyes are closed and the lids are darkly bruised.

U.S. officials also released photos of the brothers when they were alive for comparison, as well as X-rays of Uday -- who was hurt in the leg in an assassination attempt in the 1990s.

Senior defense officials told Fox News that the bodies were not repositioned in any way and that the pictures were not altered. U.S. officials are still awaiting official autopsy results.

"Now, more than ever, the Iraqis can know that the former regime is gone and is not coming back," President Bush said in Philadelphia shortly after the pictures were released.

Defense Secretary Donald Rumsfeld and Paul Bremer, the U.S. civilian administrator in Iraq, planned to hold a news conference at the Pentagon at 2 p.m. EST.

Arab satellite station Al Jazeera and another Arabic channel were showing the pictures over and over in Iraq and the Arab world, while celebratory gunfire was going off in Iraq.

The Iraqi Media Network (search), established by the U.S.-led coalition, may also broadcast the pictures, and Iraq's U.S.-backed newspaper will include them in a special edition.

Coalition aircraft also may drop leaflets containing the photographs so that all Iraqis get the word that Saddam's sons are dead.

Defense officials earlier told Fox News that Uday may have committed suicide, pointing to a "major head wound" suffered during the raid on a house in Mosul (search) on Tuesday.

But one senior defense official said later that there simply is not enough evidence in the photos to determine that Uday took his own life.

Both bodies have visible shrapnel wounds. While suicide is a possibility, officials said they will wait for autopsy results before making any conclusions.

Military sources told Fox News that Uday and Qusay "looked" to have tried to change their appearance. Uday appears in the death photos with a shaved head and a long beard, a new addition to his look. Qusay has longer hair -- perhaps down to his shoulders -- than he had been previously seen with, as well as a fuller beard.

In Baghdad, some members of Iraq's Governing Council were shown the brothers' bodies, which are being kept at Baghdad International Airport, said a spokesman for the Coalition Provisional Authority (search).

The authority also was talking with council members about how to release pictures of the bodies to the public, the spokesman said on condition of anonymity. Many Iraqis likely will be skeptical of the U.S. account without proof of the brothers' deaths.

"There isn't the slightest doubt in our minds that these are the bodies of Uday and Qusay," the spokesman said.

Fox News foreign affairs analyst Dennis Ross said showing the pictures to Iraqis -- and the world -- is critical if the coalition wants to eliminate some of the fear the Iraqi people have been living in.

"What we have to do is prove what we were saying, especially on an issue like this," Ross said. "Psychologically, it's critical and just in terms of our own credibility, it's required."

Retired military intelligence officer Timothy Lomperis told Fox News that it's very unusual for the U.S. military to show pictures like this, but it's obviously a much-needed move in this situation.

"It's a powerful symbol of the end of a brutal regime," Lomperis said. "I think the most powerful will be the capture of Saddam himself."

U.S. officials have always hoped that as more regime members are caught, more Iraqis will come forward with information as to where the others -- most importantly, Saddam himself -- are hiding.

And the day Saddam is caught or killed could be near, experts say.

"I think it should lead us very soon to the father; the father can't be far away from the sons," Lomperis said. "I think it's a matter of just days before the regime in its entirety is gone."

Uday and Qusay were killed Tuesday when 200 U.S. troops stormed a house in Mosul where they were staying.

After coming under fire during repeated attempts to enter the building, troops attacked with helicopters, grenades, heavy machine guns and anti-tank missiles. It's  believed that heavy tow missiles actually caused the sons' deaths.

For Uday, dental records matched 90 percent -- a 100 percent match could not be made because of injuries sustained in Tuesday's attack. The dental match for Qusay was 100 percent, the U.S. military said.

"Autopsies will follow, but we have no doubt we have the bodies of Uday and Qusay," Lt. Gen. Ricardo Sanchez said. "The Saddam Hussein regime will never come back to power."

Senior defense officials on Wednesday confirmed to Fox News that four formerly high-ranking Iraqi officials in coalition custody were shown the bodies for a positive ID. One of those was former Deputy Prime Minister Tariq Aziz.

Another was Abid Hamid Mahmud Al-Tikriti, Saddam's top aide who surrendered June 17 and was the ace of diamonds in the U.S. military's 55-most-wanted deck of cards.

Only 18 of the original 55 most-wanted are still at large. Uday and Qusay were Nos. 2 and 3 on the list.

Fox News' Bret Baier and Greg Palkot and The Associated Press contributed to this report.