Attorneys for detainees at the Guantanamo Bay prison said yesterday that they will quickly seek court review of their clients' detentions as the government began to consider how to comply with the U.S. Supreme Court ruling ordering access to federal courts for the 595 captives at the military jail in Cuba.

"We'll go into federal district court [in Washington] very quickly to seek access to our clients" as a first step toward seeking court hearings, Joseph Margulies, an attorney for some of the detainees, told reporters yesterday.

Yesterday's Supreme Court decision on the alleged al Qaeda and Taliban fighters at Guantanamo Bay leaves it to the government to craft a plan under which federal judges can review the evidence against the captives, and officials offered few details on how that might be accomplished.

But experts agreed that the ruling undermines the U.S. government's determined effort to seal off the environment at Guantanamo Bay for interrogating detainees without interference from courts, lawyers and the outside world.

In another decision yesterday, the court similarly provided the means for U.S. citizen Yaser Esam Hamdi to contest his detention as an "enemy combatant." The court ruled that Hamdi, who was captured on the battlefield in Afghanistan and has spent more than two years in a South Carolina military brig, must have access to the U.S. legal system.

In a third ruling, the justices returned the case of another U.S. citizen, Jose Padilla, to lower courts on jurisdictional grounds. Padilla is expected to enjoy the benefits of the ruling in Hamdi's case.

Federal public defender Frank W. Dunham Jr., who represents Hamdi, pledged to meet his client later this week to begin mapping out a strategy for an eventual habeas corpus hearing. Hamdi, who was born in Louisiana but raised in Saudi Arabia, was captured on a battlefield in Afghanistan, U.S. officials said.

Padilla's attorney, Donna R. Newman, said that she would immediately file a challenge in federal court in South Carolina. His case had been heard in federal court in New York, which the justices ruled did not have jurisdiction.

Until now, the two attorneys have met with their clients only at the discretion of the Pentagon. Military minders have attended and videotaped the sessions, and the attorneys have been prohibited from discussing the meetings publicly.

A senior Justice Department official said that an initial reading of the opinions leaves much to be determined, including the process for bringing the detainees into the federal court system and how courts will balance the need to keep sensitive military intelligence secret while protecting the rights of the accused.

The official said the rulings create the potential for an onslaught of more than 590 cases that could be filed in any number of district courts, though the official said the Justice Department probably would argue that the cases should be heard in a single court.

The official also acknowledged that hearings could interfere with the military's intelligence gathering operation, especially cases in which high-level detainees have been kept isolated and in which important classified intelligence is involved.

"There's definitely that potential, and we'll be arguing in lower courts for ways to minimize the interference with the intelligence gathering process," the official said. "There's enough language in the various opinions that shows there's a continuing need for deference to the military, and it's consistent with the military's need to handle detainees in certain ways."

Yesterday's rulings did not address the legality of the military tribunals that the government has planned for an initial group of six Guantanamo Bay prisoners, nor was it clear whether the ruling would affect an annual review procedure for the detainees established by the Pentagon.

Government intelligence experts said the court's decision would have no impact on CIA operations, including its detentions of al Qaeda detainees in undisclosed locations. "The opinion is written narrowly only to refer to Guantanamo Bay," said one government lawyer in the intelligence arena. "As for people held by the agency or elsewhere, the case is silent on that."

The next step is for the U.S. government to outline formal procedures that would grant the Guantanamo Bay inmates access to U.S. courts that human rights lawyers have sought for more than two years. Experts speculated that these could be sessions at the prison on the U.S. Navy base in Cuba or in federal courthouses in this country.

But soon after the government files its response to the Supreme Court ruling, attorneys for the detainees said they will make their case in court. "Our position is that our clients did nothing to justify their detention," Margulies said. "The decision means the government now must justify their detention in federal court."

Thomas Wilner, a Washington lawyer for 12 Kuwaiti detainees, said he will file court papers "very quickly" to demand information on his clients' physical condition and to hold the required hearings.

Eugene R. Fidell, president of the nonprofit National Institute of Military Justice, said the decision may prompt the military to demonstrate publicly that its planned annual review panels for the detainees are fair and defensible. Attorneys for the detainees have contended that these reviews and the tribunals are skewed against prisoners. One military lawyer for a Guantanamo detainee who faces a tribunal has filed a petition in federal court seeking to halt the tribunals on the grounds that they violate U.S. and international laws.

"The Supreme Court decision will have a chastening effect on the government, reminding it that it must mind its p's and q's," he said.

It is not clear that all 595 detainees or their families have lawyers. Attorneys said yesterday that U.S. military officials should feel obligated under the spirit of the Supreme Court ruling to notify all detainees that they have won the right to hearings.

Defense lawyer Margulies said he will argue in future habeas hearings that the government should not be allowed to cite evidence gathered in interrogations in which "coercive" tactics were used. U.S. officials have acknowledged high-level approval was given at various times to use physical and psychological pressure in seeking information from Guantanamo Bay detainees.

Yesterday's Supreme Court decisions did not directly address the case of Ali S. Marri, a Qatari national designated as an enemy combatant by President Bush last year who is being held at the Navy brig in Charleston along with Hamdi and Padilla. U.S. officials suspect that Marri, who came to the United States as a student, is an al Qaeda operative.

His lawyer, Lawrence Lustberg, said he plans to file a motion in the next few weeks in South Carolina, arguing that his client deserves a day in court. Lustberg said he plans to cite yesterday's Hamdi and Guantanamo Bay decisions.

"We hope to see him as soon as possible . . . and to get all the rights that the Supreme Court has now accorded him," Lustberg said.

Staff writers Josh White, Dana Priest and Michelle Garcia contributed to this report.