Attorney General John Ashcroft said Tuesday that the Al Qaeda network faced a serious blow with the weekend arrest of Khalid Shaikh Mohammed, and the terrorist operation is suffering badly as a result.

"Next to (Usama) bin Laden, Khalid Shaikh Mohammed was the FBI's most wanted terrorist," Ashcroft told Senate Judiciary Committee members.

Bin Laden may be the face, but Mohammed "was the operational mastermind," added FBI Director Robert Mueller. "His terrorist plots are believed to include the 1993 World Trade Center, the USS Cole bomb delivered by boat and the September 11 terrorist attacks delivered by air, having resulted in the deaths of thousands of innocent people."

Lawmakers offered praise of the Bush administration for the arrest of Mohammed, but some warned that the government has a long way to go in wrapping up the war on terror.

Committee chairman Orrin Hatch, R-Utah, told Ashcroft, Mueller and Homeland Security Secretary Tom Ridge that the arrest represents a "striking example" of the Bush administration's commitment to the global war against terrorism.

"The apprehension of Khalid Shaikh Mohammed is just one more success in a string of successes by you and others in the law enforcement and intelligence community aimed at disrupting and eliminating Al Qaeda from the face of this earth," Hatch said.

But Sen. Patrick Leahy, D-Vt., the ranking member on the committee, said that he doesn't want to see more authority handed over to law enforcement, particularly a controversial proposal by the Justice Department to expand the USA Patriot Act, until the Patriot Act has been properly evaluated.

The Patriot Act increased law enforcement abilities to pursue terror suspects, but many have suggested that it has put a dent in personal liberties of innocent people wrongly investigated and misapplied by law enforcement who don't know how to follow procedures and have missed the opportunities provided by the Act.

"If there's going to be a sequel let's find out what it's going to be" before reading about it in the newspapers, Leahy said, accusing the Justice Department of lying to his staff about whether a new bill was in the works.

As head of the Justice Department, Ashcroft, who was cut off from responding to Leahy's accusation, did not address the new proposal in his prepared testimony, but said that the Patriot Act has created an environment in which law enforcement has successfully prosecuted in the war on terror, including the arrest of two alleged Islamic terrorists last month in a sting operation at a hotel near Frankfurt Airport in Germany.

Ashcroft announced that prosecutors for a federal court in Brooklyn unsealed a complaint Tuesday against Yemeni cleric Sheik Mohammed Ali Hasan al-Moayad, being held in Germany for secretly raising money and recruiting troops for Al Qaeda and Hamas.

"The FBI undercover operation developed information that al-Moayad personally handed Usama bin Laden $20 million from his terrorist funding network," Ashcroft said.

"Today Americans are safer because we have transformed the rules of engagement" for investigating suspected terrorist links, Ashcroft said, referring to changes in the Patriot Act that opened up investigations conducted under the Foreign Intelligence Surveillance Act.

FISA enables law enforcement to pursue terrorists using less than traditional surveillance methods.

"We rewrote the FISA procedures and directed prosecutors to change their procedures," reducing the risks previously borne by FISA rules that limited the intelligence exchanged between the FBI, CIA and other agencies," Ashcroft said.

Last week, Leahy and Sens. Arlen Specter, R-Pa., and Charles Grassley, R-Iowa, said the FBI and Justice Department had misused the laws for failing to learn how to use the procedures to get the wiretaps and other surveillance needed to target terror suspects.

"September 11 might well have been prevented," Specter said. "What are they doing now to prevent another 9/11?"

Sen. Russ Feingold, D-Wis., and other Democrats say they've been asking Justice officials for months for their ideas on expanding the anti-terrorism statutes but have been rebuffed.

Ashcroft repeated that no decisions have been made on a final proposal for an anti-terrorism expansion, although officials were working with "a full range of ideas."

The hearing, ACLU executive director Anthony Romero said, should "really get at the heart of the matter, to determine whether any of the powers they have already been granted have really made us any safer."

The original USA Patriot Act, Romero said, was pushed quickly through Congress in the aftermath of the Sept. 11 attacks. "Congress did not bother to ask the hard questions," he said. "It was seen as somehow unpatriotic.

"With calmer minds and cooler tempers, we can go back and look at the powers we gave after 9/11. Do we really need these powers? Do these powers make us any less free as a nation?" he said.

While Leahy expressed concerns with the law, Hatch has expressed clearly that he would support additions to the Patriot Act, arguing in a letter last week that he doesn't believe law enforcers would be limited by "requirements that go above and beyond those required by the Constitution."