WASHINGTON — Revelations that the government collected the phone-call records of millions of Americans touched off a political firestorm Thursday, prompting calls for a congressional investigation and fueling opposition to President Bush's choice for CIA director.

USA Today reported Thursday that at least three companies — AT&T, Verizon and BellSouth — turned over call records for tens of millions of their customers to the National Security Agency as part of the Bush administration's war on terrorism. Another company, Denver-based Qwest, refused to cooperate because it questioned the legality of the government program.

Critics said the massive collection of phone records violates Americans' privacy and raises disturbing questions about the government's reach into personal lives.

"Are you telling me that tens of millions of Americans are involved with al-Qaida?" Sen. Patrick Leahy, D-Vt., asked. "If that's the case, we've really failed in any kind of a war on terror."

Sen. Arlen Specter, R-Pa., the chairman of the Senate Judiciary Committee, said he would summon telephone company executives to a hearing that would examine how much customer information they supplied to the government.

"And we intend to pursue that to try to find out what's going on and whether it's constitutional," Specter said.

At a hastily arranged appearance before reporters, Bush insisted that everything the government is doing is legal.

"Our intelligence activities strictly target al-Qaida and their known affiliates," Bush said. He added assurances that the privacy of Americans is being "fiercely protected . . . We're not mining or trolling through the personal lives of millions of innocent Americans."

The call logs didn't identify individual customers, the newspaper said, but government investigators could find that information easily by tracking down phone numbers that they consider suspicious.

The call logs are intended to help the government zero in on suspicious phone calls through a process known as data mining. Administration officials insist that the government doesn't eavesdrop on calls within the United States without warrants.

Bush established a secret surveillance program at the NSA without congressional approval shortly after the terrorist attacks on Sept. 11, 2001. The program targets communications between suspected foreign terrorists and individuals in the United States. Bush contends that government agents can eavesdrop on the domestic end of suspicious international calls without court-approved warrants. Many constitutional scholars, and some lawmakers in both parties, disagree.