Attorney General Alberto Gonzales refused to say today whether the National Security Agency's domestic surveillance program had opened first-class mail. Gonzales is testifying before the Senate Judiciary Committee, which is holding hearings into the legality of President Bush's spying on Americans.

Gonzales was called to testify in part so that he could try to explain why President Bush ordered American phones wiretapped and e-mail searched by the NSA without approval from the spy court known as FISA, short for Foreign Intelligence Surveillance Act.

Gonzales also told the Senate committee that information from the surveillance is "collected and retained." Whether the intelligence gathered in this way could be held and used in other cases or for other purposes is unclear. Gonzales would not say whether surveillance information was used in programs other than the NSA intercepts.

And he refused to answer a question from California Democratic senator Dianne Feinstein on whether he believes the posse comitatus act could be suspended. That act prohibits the military from intervening in domestic affairs.

The Bush administration has repeatedly insisted it informed leaders of both parties in Congress before the NSA programs was begun. Feinstein has said that when the White House sought to insert language approving electronic surveillance "inside the U.S." into legislation, Tom Daschle, then minority leader, had replied, "absolutely not."

In answer to a question from Republican senator Mike DeWine of Ohio, Gonzales said that despite an increase in staff, it still "takes too long to get FISA's approved," adding, "My applications are often an inch thick. . . . Members of the FISA court are heroes. . . . They are killing themselves making themselves available to sign off," but they're just not fast enough.

The subject of opening mail came up in this exchange between Gonzales and Democratic senator of Vermont this morning when the senator asked whether Bush believes his supposed authorization would be enough to allow the government to open people's mail.

"There is all kinds of wild speculation out there about what the president has authorized and what we're actually doing," Gonzales said.

"You're not answering my question," Leahy retorted.

"Does this law authorize the opening of first-class mail of U.S. citizens? Yes or no?"

"That's not what's going on," Gonzales said. "We are only focusing on international communications, where one part of the conversation is al Qaeda."

Gonzales later confused the senators by saying transmissions within the U.S. among al Qaeda individuals and cells were not covered by the NSA program. The attorney general elaborated on this point, saying that other laws covered intercepts of such transmissions, and that the Justice Department was monitoring those intercepts.