The United States has announced a reward of up to $25 million for information leading to the arrest of Saddam Hussein, or conclusive proof that the ousted Iraqi leader is dead. Rewards are also being offered for help in the capture of the former dictator's sons, Uday and Qusay.

More than three months have passed since the U.S.-led coalition toppled the Saddam Hussein government, but there is still no conclusive word on the fate of the former leader and his sons.

Officials here say the decision to offer the rewards is aimed at helping remove once-and-for-all the questions about their fate, and what they say is lingering fear in Iraq that the ousted leader might somehow stage a comeback.

In a talk with reporters here, Secretary of State Colin Powell said he signed off on the reward initiative program earlier Thursday, after a lengthy debate within the administration.

"It's authority that we have, and we're using that authority," he said. "We believe it's important to do everything we can to determine his whereabouts, whether he is alive or dead, in order to assist in stabilizing the situation, and letting the people of Baghdad be absolutely sure that he's not coming back. And this is just another tool to be used for that purpose."

The rewards were announced in Iraq by U.S. administrator Paul Bremer, who called Saddam Hussein and his sons "some of the most evil men the world has known."

Mr. Bremer said they may or may not be alive, but until their fate is known for sure, their names will continue "to cast a shadow of fear" over the country.

Mr. Bremer said the uncertainty about Saddam Hussein "clearly gives an impetus" to former Baath party loyalists, who are still active in the country and linked to attacks on coalition military personnel.

However, State Department spokesman Richard Boucher insisted under questioning that the doubts have not presented any insurmountable obstacle to Iraqi reconstruction, or the effort to build a new democratic political system.

"It may have some psychological effect on the situation, and we think it is an important element to remove that uncertainty," said Richard Boucher. "But at the same time, I don't think it's impeded the real effort going to restore services to the Iraqi people, to get them more and more involved in a political process that can lead to the kind of Iraq where they're in charge, and able to live in freedom and without fear of this kind of dictatorship and cruelty again."

The rewards are being offered under the State Department's "Rewards for Justice" program, which has had some success in helping locate fugitives wanted for war crimes in the Balkans and central Africa.

The $25 million reward for Saddam Hussein is the same as that still being offered for information leading to the capture of terrorist leader Osama bin Laden. Up to $15 million would be paid for information leading to the capture of either of the former Iraqi leader's two sons.