WASHINGTON -- In a dramatic setback for the Bush administration, a federal judge yesterday ordered the government to release immediately and transfer to the U.S. mainland 17 Chinese-born Muslims detained for almost seven years in the U.S. military detention center at Guantanamo Bay, Cuba.

The decision marked the first time a court has ordered the transfer of Guantanamo detainees to the United States and could prompt the release of dozens of other Guantanamo detainees who have been cleared for release by the military, but who cannot leave because the government has not yet found a country to which to send them.

Judge Ricardo Urbina declared the continued detention of the group from China's ethnic Uighur minority to be "unlawful," and ordered the government to bring the detainees to the United States by Friday.

Reading his decision from the bench, Judge Urbina said the government could no longer detain the Uighurs after conceding that they weren't enemy combatants. The judge also agreed with the Uighurs' lawyers, who have argued that the group cannot be returned to China because they could face torture there.

Judge Urbina warned the government not to try to circumvent the group's release by detaining them on immigration holds once they reach the United States, saying: "No one is to bother these people until I see them."

Administration officials said they intended to file an "emergency motion" last night with the federal appeals court in Washington to block the ruling.

"This decision, we believe, is contrary to our laws, including federal immigration statutes passed by Congress," said White House spokeswoman Dana Perino. "The district court's ruling, if allowed to stand, could be used as precedent for other detainees held at Guantanamo Bay, including sworn enemies of the United States suspected of planning the attacks of 9/11, who may also seek release into our country."

Judge Urbina, who at times during the hearing appeared to scold Justice Department lawyers, noted that the government had not charged the Uighur detainees with any crime, revealed any evidence justifying their detention and then "stymied" their release by continuing to assert erroneously that they were enemy combatants.

When government lawyers started to raise security concerns, the judge challenged them to specify what they were, chiding them that "you've had seven years to study this." He described the government's use of certain legal jargon as "Kafkaesque," saying it "begs the question of whether they ever were enemy combatants."

Supporters from the Uighur-American community who attended the hearing reacted to his ruling with loud applause and cheers. "The American system has given us justice," said Rebiya Kadeer, president of the World Uighur Congress.

Citing "serious separation-of-power issues," Justice Department lawyers immediately requested a delay to allow the government time to consider whether to appeal. The judge refused, however, and instead set a hearing to determine the conditions for release.

Despite the prospect of the government's appeal, Ms. Kadeer said: "I believe they will be released." Ms. Kadeer, a leader of the expatriate Uighur community, was once detained for several years in a Chinese prison as a political dissident, but released and sent to the United States after the State Department pressured the Chinese government.

Judge Urbina, a Clinton appointee, said the men will be permitted to stay with Uighur families in the Washington area, but will be expected to check in with the court regularly. Next week, the court will consider whether to impose other conditions upon their release.

The Uighurs were first shipped to Guantanamo from Afghanistan after their capture by U.S. troops at a weapons training camp. The military accused the group of being members of the East Turkistan Islamic Movement and said the camp in Afghanistan's Tora Bora mountains was run by the Taliban. But the Uighurs denied being members of the group or receiving Taliban support.

The Uighurs also have insisted that they consider the United States to be an ally in their fight for more political freedom in China. Declassified documents turned over to their lawyers showed that, as early as 2003, government officials had concluded that they were not enemy combatants and had recommended releasing them.

Attorneys representing the group hailed yesterday's ruling as a landmark and predicted that it could lead to more releases.

"The decision is extraordinary," said one attorney, Neil McGaraghan. "This is finally a step toward justice."

The decision comes after a three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit overturned as "invalid" a military tribunal's conclusion that one of the detainees, Huzaifa Parhat, is an enemy combatant. The court, the same one that could hear the Justice Department appeal, directed the Pentagon either to release or transfer Mr. Parhat or hold a new tribunal hearing "consistent with the court's opinion."

After the appellate ruling, the government conceded that it no longer considered any of the Uighurs to be enemy combatants.