Nearly six years ago, Bosnian authorities ordered the release of six men picked up on suspicion of plotting to attack the U.S. Embassy in Sarajevo. An investigation found no evidence against the six Algerian natives.

Instead of freedom, however, they got a trip to the U.S. naval base at Guantanamo Bay, Cuba. They were branded enemy combatants by the Bush administration and have been held since. They have not been charged with a crime.

On Wednesday, the Supreme Court will consider whether the Algerians and about 300 other prisoners at Guantanamo can go to U.S. courts to challenge their confinement. Just three detainees are facing charges at the moment, although Pentagon officials have talked about eventually holding military trials for 60 to 80 prisoners.

The prisoners want the justices to order prompt court hearings, considering the length of their detention so far.

The cases to be argued Wednesday mark the third time that the Supreme Court has examined the rights of the detainees. Twice before, the court has ruled against the administration. Each time Congress and the White House have changed the law in an effort to keep the Guantanamo prisoners from contesting their detention before American judges.

The indefinite detentions have become a focal point of international criticism of the administration's fight against terrorism, with increasing calls for closing the Guantanamo facility.

The administration is mounting a vigorous defense of its detention policies.

In a court filing, the administration's top Supreme Court lawyer says the cells at Guantanamo hold people suspected of plotting terrorist attacks or with ties to the al-Qaida terrorist network and the Taliban who formerly ruled Afghanistan. Moreover, the detainees "enjoy more procedural protections than any other captured enemy combatants in the history of warfare," Solicitor General Paul Clement says.

Despite the prisoners' six years of confinement, Clement says the justices should not upset the detainees' classification as enemy combatants "at this preliminary stage," even if the court rules that the detainees can be heard in U.S. courts.

The case turns on the reach of the writ of habeas corpus. The centuries-old legal principle, enshrined in the Constitution, allows courts to determine whether a prisoner is being held illegally.

The government says foreigners held outside the United States have no constitutional rights and that Congress has stripped federal courts of jurisdiction in the detainee cases.

Even if the detainees have rights, the procedures put in place to review their status as enemy combatants are adequate, Clement says.

The case has attracted 26 court filings on behalf of the detainees. Among those weighing in are Canadian and European lawmakers; former U.S. judges, diplomats and military officers; Israeli law professors; human rights organizations; liberal interest groups; the libertarian Cato Institute; and Sen. Arlen Specter, R-Pa.

Four legal briefs, from retired military officers, national security organizations and conservative public interest law firms, are supporting the administration.

Jonathan Hafetz, a lawyer for the detainees, said the case tests "whether the U.S. can establish lawless enclaves, prisons beyond the law."

The detainees' lawyers say most were not seized on a battlefield, but rather were handed over by local warlords in Afghanistan and Pakistan for large bounties. Others, like those in Bosnia, were picked up far from the fighting in Afghanistan.

They were moved to the U.S. base in Cuba beginning in early 2002, a few months after the attacks of Sept. 11, 2001.

The justices initially turned down the detainees' latest appeal, but reversed course in June. They provided no explanation. But their action followed a declaration from a military officer who alleged the U.S. military panels that classified detainees as enemy combatants for the past four years relied on vague and incomplete intelligence.

The detainees' lawyers feel good about their chances at the Supreme Court because five of the nine justices must agree to take a case that previously has been denied a hearing. Ordinarily, just four justices must vote to hear a case.

Attached to the Algerian-Bosnian detainees' appeal are excerpts from the review panel that considered whether one of them, Mustafa Ait Idir, had been properly classified an enemy combatant.

The government said Idir associated "with a known al-Qaida operative" and planned to attack the embassy. He was not given the name of the operative or any evidence linking him to the plot.

"If a supervisor came to me and showed me accusations like these, I would take these accusations and I would hit him in the face with them," he said, interrupted by laughter from everyone in the room, according to the transcript. "Why? Because these are accusations that I can't even answer."

The cases are Boumediene v. Bush, 06-1195, and Al Odah v. U.S., 06-1196.