President Bush today denied that the government is "mining or trolling through the personal lives of innocent Americans," as Democrats expressed outrage over a news report describing a National Security Agency program that has collected vast amounts of telephone records.

The article, in USA Today, said that the agency did not listen to the calls, but secretly obtained information on numbers dialed by "tens of millions of Americans" and used it for "data mining" — computer analysis of large amounts of information for clues or patterns to terrorist activity.

Making a hastily scheduled appearance in the White House, Mr. Bush did not directly address the collection of phone records, except to say that "new claims" had been raised about surveillance. He said all intelligence work was conducted "within the law" and that domestic conversations were not listened to without a court warrant.

"The privacy of all Americans is fiercely protected in all our activities," he said. "Our efforts are focused on Al Qaeda and their known associates."

In the Senate, Democrats denounced the article as evidence that Congress had failed to carry out its duty to make sure that the intelligence activities did not violate civil rights.

And Senator Arlen Specter, the chairman of the Senate Judiciary Committee, said he would call executives of AT&T, BellSouth and Verizon "to see if we can learn some of the underlying facts."

He said he would question them about "what we can't find out from the Department of Justice or other administration officials."

The article named those three companies as cooperating with the security agency's request; it said that Qwest had refused to provide the information.

The New York Times reported last December that the agency had gathered data from phone and e-mail traffic with the cooperation of several major telecommunications companies.

But Democrats reacted angrily to the USA Today article and its description of the program's vast size, including an assertion by one unnamed source that its goal was the creation of a database of every phone call ever made within the United States' borders.

"Are you telling me that tens of millions of Americans are involved with Al Qaeda?" Senator Patrick J. Leahy of Vermont, the committee's ranking minority member, asked angrily.

Like Mr. Specter, Mr. Leahy made a link between the new charge and the administration's refusal to answer the many of the committee's questions about the security agency's warrantless wiretaps of calls between the United States and overseas in which one person is suspected of terrorist ties.

"It's our government, our government!" he said, turning red in the face and waving a copy of USA Today. "It's not one party's government, it's America's government!"

Other Democrats demanded that the administration officials, including Attorney General Alberto Gonzalez and former Attorney General John Ashcroft, be subpoenaed to testify under oath about both programs.

And they made clear that they thought the new surveillance issue would complicate the nomination of Gen. Michael V. Hayden, a former head of the security agency, to be the new director of the Central Intelligence Agency.

"I want to ask General Hayden about these programs before we move forward with his nomination, which I was inclined to be supportive of, if he showed the requisite independence," said Senator Charles E. Schumer, a New York Democrat and member of the Judiciary Committee.

Republicans urged caution before drawing any conclusions based on the article, and noted that it described the program as collecting information only about phone numbers, not about the contents of conversations.

"It's not a wiretapping program, it's simply a compilation, according to the report here, of numbers that phone companies maintain," said Senator Jeff Sessions of Alabama, who is also on the judiciary panel.

He compared it to "mail covers" and "pen registers," techniques long used by law-enforcement authorities to record the addresses on letters or calls made by individuals under investigation. No warrant is needed for such efforts, but the government must certify with a court that the information likely to be obtained is relevant to an ongoing investigation.

But at least one prominent Republican expressed reservations. "I am concerned about what I read with regard to N.S.A. databases of phone calls," Representative John A. Boehner of Ohio, the House majority leader, told The Associated Press.

Senator Dianne Feinstein, the California Democrat who is a member of the Intelligence Committee as well as the Judiciary Committee, appeared to confirm at least the gist of the article, while stressing that what was under discussion was not wiretapping. "It's fair to say that what is in the news this morning is not content collection," she said.

Even so, she warned, "I happen to believe that we are on our way to a major Constitutional confrontation on the Fourth Amendment guarantees over unreasonable search and seizure."

Senator Russell D. Feingold, a Wisconsin Democrat who is also on both the judiciary and intelligence panels, expressed dismay over what he termed the administration's "arrogance and abuse of power." He said the United States can fight terrorism and still protect privacy, "but only if we have a president who believes in these principles."

The Times article disclosing the data mining program last December quoted officials in the government and the telecommunications industry who have knowledge of parts of the program as saying the N.S.A. has sought to analyze communications patterns to glean clues from details like who is calling whom, how long a phone call lasts and what time of day it is made, and the origins and destinations of phone calls and e-mail messages. Calls to and from Afghanistan, for instance, are known to have been of particular interest to the N.S.A. since the Sept. 11 attacks, the officials said.

The telephone companies today declined to comment on the article, and would say only that they are assisting government agencies in accordance with the law, The Associated Press reported.

"We have been in full compliance with the law and we are committed to our customers' privacy," said Bob Varettoni, a spokesman for Verizon.

In the USA Today article, the White House defended its overall eavesdropping program and said no domestic surveillance is conducted without court approval.

"The intelligence activities undertaken by the United States government are lawful, necessary and required to protect Americans from terrorist attacks," said Dana Perino, the deputy White House press secretary, who added that appropriate members of Congress have been briefed on intelligence activities.

The anger among committee members carried over to a number of other related developments. Senator Specter said he was sending a letter to the Justice Department in response to a news report that an investigation by the Justice Department's ethics office into the lawyers who gave approval to the domestic surveillance program was abandoned because the investigators were refused the necessary security clearances.

"It's sort of incomprehensible that that was done," Senator Specter said, adding that he was asking that the clearances be granted so the review could continue.

Senator Richard J. Durbin, an Illinois Democrat on the Judiciary Committee, called the decision "clear evidence of a cover-up within this administration."

Mr. Specter also said that he "had some indication" that Mr. Ashcroft and James Comey, a former deputy Attorney General, had some knowledge about the domestic surveillance program, but said he didn't think it would be "fruitful" to subpoena them to testify.

And Mr. Specter said that he believed he had the agreement of all 10 Republicans on the committee for a bill he has proposed that would ask the special court that handles requests for warrants on foreign intelligence to rule on the Constitutionality of the domestic surveillance program.

But several Democrats indicated that they were not likely to support the bill in the absence of more information about the surveillance the government is conducting in general.

"How can we approve this without knowing much more?" asked Mr. Durbin.