WASHINGTON - The nation's spy court said yesterday that it would not release its documents regarding the Bush administration's program of warrantless wiretapping.

In a rare public opinion, the Foreign Intelligence Surveillance Court said the public had no right to view the documents because they dealt with the clandestine workings of national security.

The American Civil Liberties Union asked the court in August to release the records. Specifically, the ACLU asked for the government's legal briefs and the court's opinions on the wiretap program.

U.S. District Judge John D. Bates, who sits on the national security court, refused. Releasing the documents would reveal secrets that enemies could use to evade detection or disrupt intelligence activities, he said. Sources could be revealed, targets tipped off, or diplomatic ties damaged, he said.

"All these possible harms are real and significant and, quite frankly, beyond debate," Bates wrote.

Among the documents the ACLU sought were court orders that allowed the Bush administration to bring the wiretapping program under the court's purview in January. Previously, the Terrorist Surveillance Program allowed investigators to monitor international phone calls and e-mail to or from the United States without court oversight.

The Bush administration said in January that it no longer needed that program because the spy court had established satisfactory standards. The ACLU wanted to know what those standards were and how they were justified.

The ACLU also wanted to know about a later ruling by the court that barred the government from eavesdropping on foreign suspects whose messages were routed through U.S. communications carriers, including Internet providers. That ruling helped President Bush persuade Congress to pass an overhaul of the Foreign Intelligence Surveillance Act, which governs such wiretapping.

Exactly what the court said, and why, is not publicly known. But Congress agreed to a plan in which the director of national intelligence and the attorney general can approve wiretaps without having to go before the court. The court would get involved whenever a U.S. citizen is the primary target of surveillance.

"Without access to those judicial rulings, the public has no idea what government's surveillance powers are," ACLU lawyer Jameel Jaffer said. "It shouldn't be a controversial proposition that the public has a right to know what the court believes the scope of FISA is."

Bates acknowledged the public would benefit from seeing the documents. The decision-making process would be understood, he said, and public oversight could help safeguard against government abuse. But the dangers of releasing such sensitive materials far outweigh that public benefit, he said.

Public opinions from the spy court are so rare, it's not immediately clear what the ACLU's options are.

Because Bates alone signed the ruling, the group might be able to ask for a review by the full panel. Or, it might be able to challenge the ruling before a federal appeals court.