Updated

U.S. officials in Iraq have solid evidence of weapons of mass destruction (search) programs and details probably will be released soon, two leading Senate Republicans said Thursday, after returning from Iraq.

But Democrats on the same trip said the evidence wasn't definitive. They said the Republicans were trying to shift the focus from proving that Saddam Hussein (search) had weapons to proving he was developing them.

"That was not the basis on which the nation went to war," said Sen. Jay Rockefeller of West Virginia, top Democrat on the Senate Intelligence Committee.

The lingering difference over Iraq's weapons programs was the only public partisan dispute among the nine-member delegation led by Sen. John Warner (search), R-Va., the Armed Services Committee chairman. The delegation included members of his panel and the Intelligence Committee leaders. The senators spent three days in Iraq.

Warner and other senators at a news conference stressed the need for a long-term commitment to rebuild Iraq and bring it stability. They also emphasized a need to capture Saddam or prove he's dead. While doubts remain about Saddam's fate, many Iraqis will be reluctant to cooperate with Americans, fearing he will return, Warner said.

Warner said he doesn't believe Saddam is behind attacks against U.S. soldiers.

"This guy is not, to the best of all those who have facts, trying to coordinate any of these attacks," Warner said. "This guy is slinking around, each day hiding and running, some say in a crude disguise, some say manifesting the effects of having been wounded. We'll get him."

U.S. officials announced a $25 million reward Thursday for information leading to the capture of Saddam or confirmation of his death. Secretary of State Colin Powell said "it is 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."

On the search for weapons of mass destruction, Intelligence Committee Chairman Pat Roberts, R-Kan., said "it's going to take additional time to uncover Saddam's weapons programs." He stressed that he was not talking about "the finished product, but the program."

But he said there have been "breakthrough pieces of information" about the weapons programs and he believed "there's going to be breaking, positive news on that front in a very near term."

Later, in a separate news conference, Roberts said he was urging the Bush administration to make some of the information public. "We've had some success; I'm sorry I can't go into detail about that," he said.

Warner said that from highly classified information provided to the senators "any fair-minded, objective individual ... will clearly come to the conclusion that these weapons did exist, that they were in the hands of those who could use them, and thank God they weren't used."

But the top Democrat on Armed Services, Sen. Carl Levin of Michigan, said the information was "cautiously presented and with the urging that there not be a conclusion drawn."

He described it as evidence "relative to a program that could have been constituted or reconstituted with some speed."

Army Capt. Jeff Fitzgibbons, a U.S. military spokesman in Baghdad, said weapons search teams had turned up a few suspicious finds over the past 10 days and had called for an investigative team with a mobile laboratory truck to test the samples. But he said he had no knowledge of a recent discovery that would provide hard evidence of a hidden weapons program.

"We had a couple incidents people are investigating to see if it's anything or not. As soon as they have anything that's even close to a smoking gun, they'll come out with it," Fitzgibbons said.

Levin distinguished between finding a program and administration claims that Saddam already had chemical or biological weapons. "If you got artillery shells or chemicals which are right there, ready to be used, that is a very different thing than a program."

Questions about prewar intelligence on Iraq's weapons programs have divided the Senate. Democrats have questioned whether intelligence was inaccurate or manipulated as President Bush made his case for war. Republicans say there was no wrongdoing and have accused Democrats of politicizing the issue.

The Intelligence Committee has begun closed-door hearings on the issue. Armed Services is conducting a broad review on the war, but Warner has rejected Levin's request for an inquiry on intelligence. Levin has directed his staff to conduct its own examination.

Among the issues raising questions were two truck trailers that the CIA has said were mobile biological weapons laboratories. Some State Department analysts have questioned that conclusion.

Roberts said the CIA's special adviser for the weapons search, David Kay, "thinks the mobile labs are mobile labs, in regard to WMD." Levin said Kay told them he hadn't reached a definite conclusions but, if pressed, believed the trailers were probably weapons labs.