Washington ? Democratic lawmakers are insisting the White House turn over top-secret documents prepared for President Bush that indicated Osama bin Laden wanted to hijack U.S. airplanes.

They also want to see another pre-Sept. 11 document an FBI memo that warned headquarters that many Middle Eastern men were training at American flight schools.

Bush officials acknowledged for the first time Thursday that the president was briefed about a possible hijacking plot in early August while he vacationed at his Texas ranch. But the officials were deeply divided over whether to release the documents.

The news of Bush’s August briefing set off a furor and precipitated a public relations blitz by the White House, which sent forth an extraordinary number of senior advisers to defend the president as Democrats, and a few Republicans, sought answers.

“Why did it take eight months for us to receive this information? And what specific actions were taken by the White House in response?” Senate Majority Leader Tom Daschle, D-S.D., said. “I’m not going to jump to any conclusions, but it’s hard to understand why the information was not released.”

House Minority Leader Dick Gephardt, D-Mo., posed a variation on the famous Watergate-era question: What did the president know and when did he know it?

Republican Sen. Richard Shelby of Alabama, vice chairman of the Senate Intelligence Committee, said, “There was a lot of information. I believe and others believe, if it had been acted on properly we may have had a different situation on Sept. 11.”

But the administration argued there was no information about a specific threat and Vice President Dick Cheney warned Democrats to tread lightly.

“They need to be very cautious not to seek political advantage by making incendiary suggestions that were made by some today that the White House had advance information that would have prevented the tragic attacks of 9-11,” Cheney said. “Such commentary is thoroughly irresponsible and totally unworthy of national leaders in a time of war.”

The dispute has primarily become focused on two documents a classified CIA analysis given to Bush on Aug. 6 and a memo written even earlier in the Phoenix FBI office that warned headquarters that many Middle Eastern men were training at least one U.S. flight school.

Defense Secretary Donald H. Rumsfeld said Friday on NBC’s “Today” that he was unaware of the Phoenix memo “until it showed up in the press very recently.”

“The vast majority of the reports and scraps of information that come in tend to be eventually discounted as not being valid, or, at the minimum, not being actionable,” Rumsfeld said.

Bush’s national security adviser, Condoleezza Rice, said the intelligence, tucked in a 1-page terrorism report given to Bush, mentioned bin Laden’s al-Qaida network and “hijacking in a traditional sense” not suicide hijackers slamming fuel-laden planes into American landmarks.

“You would have risked shutting down the American civil aviation system with such generalized information,” she told reporters.

It was most likely they “would take over an airliner, holding passengers and demand the release of one of their operatives,” Rice said of the report’s reference to al-Qaida. She said the terrorists wanted to hijack a plane and demand the freedom of the “blind sheik” Omar Abdel-Rahman, the Egyptian cleric imprisoned for a plot to bomb targets in New York in the early 1990s.

The report discussed a variety of methods terrorists might deploy against the United States, including biological and chemical weapons, sources said. The only mention of hijacking was “one sentence buried in one briefing,” said a senior official, speaking on condition of anonymity.

Bush had no public comment on the developments, but, according to one participant at a closed-door meeting with GOP senators, suggested politics might be in play.

“He said if there had been a strong warning to trust him that he would have reacted quite forcefully,” said Sen. Lincoln Chafee, R-R.I., who attended the Capitol luncheon. “He reminded us this is the political season.”

Rice also described a series of threats uncovered by intelligence officials, beginning in September 2000 and reaching a peak in summer 2001, that dealt mostly with American interests overseas.

Those threats prompted a series of alerts from the FBI to law-enforcement agencies and from the Federal Aviation Administration to the nation’s airlines and airports, she said. There also were strong warnings to Americans to be careful overseas.

But the warnings to airlines were too vague to prompt action, said officials at United Airlines and American Airlines, the two carriers whose planes were hijacked on Sept. 11.

“During 2001, there were no alerts or cautions that indicated a Sept. 11th scenario was credible or possible,” United spokesman Joe Hopkins said.

Transportation Secretary Norman Mineta acknowledged the warning had no specifics. and Rice said the administration never considered alerting the public to a possible hijacking threat at home.

“Even in hindsight, there was nothing in what was briefed to the president that would suggest that you would go out and say to the American people, ‘Look, I just read that terrorists might hijack an aircraft,'” she said.

House and Senate intelligence committees are already conducting investigations into why the government didn’t foresee the attacks that killed more than 3,000 people, and destroyed the World Trade Center and a part of the Pentagon. Leaders of the committees said the administration’s revelations Thursday may signal the need for an independent investigation.

Republican leadership stepped in to defend the president.

“Democrats now say that they were kept in the dark about these threats. That is not the case,” House Speaker Dennis Hastert, R-Ill., said. “These threats were relayed on a bipartisan basis to the House Intelligence Committee in real time.”

But Rep. Nancy Pelosi, D-Calif., also a member of the intelligence committee, said the White House appears to have received more information than members of Congress.

“The questions are: What were the changed circumstances on August 7 that prompted the intelligence community to bring to the direct attention of the president information from three old reports on possible terrorist activity?” Pelosi said late Thursday. “And after raising the issue to such a high level, what actions, if any, were considered appropriate in light of this information?”

There were reasons to suspect suicide attacks with airplanes. In 1994, for example, Algerian terrorists hijacked a plane in a foiled attempt to destroy the Eiffel Tower. And in 1995, terrorists in the Philippines plotted to hijack several U.S. planes, and there was even talk of crashing into CIA headquarters.