A federal appeals court on Monday overturned a U.S. military tribunal's enemy combatant designation for a Chinese Muslim at the Guantanamo Bay prison, its first ruling that gives a detainee a chance for release.

It ordered the U.S government to release or transfer Huzaifa Parhat, a member of the Uighur ethnic group, or to "expeditiously" hold a new military tribunal for him.

Parhat, who was captured in Afghanistan and who has been imprisoned at Guantanamo Bay in Cuba for six years, is one of several Uighurs still at the prison. The United States has struggled to find a country willing to accept the Uighurs.

In 2006, the United States allowed five Chinese Muslims released from Guantanamo to seek asylum in Albania. The U.S. government has said it cannot return the Uighurs to China because they would face persecution there.

Many Muslim Uighurs, who are from Xinjiang in far western China, seek greater autonomy for the region and some want independence. Beijing has waged a relentless campaign against what it calls the violent separatist activities of the Uighurs.

The ruling by the three-judge panel was under the Detainee Treatment Act of 2005 that gave the prisoners a limited review before the appeals court of their designation as an enemy combatant.

The court also said Parhat can seek his immediate release before a U.S. District judge under the Supreme Court's landmark ruling this month that the detainees have the legal right to challenge their years-long confinement.

A key issue in the Parhat case was whether he had been involved in any activity that would justify designating him as an enemy combatant.

The government argued that Parhat was trained by a group called the East Turkestan Islamic Movement and that it has links to al Qaeda. That was enough to hold him, it said.

Parhat's lawyers said he considered China, not the United States, the enemy, and that there was no evidence that he ever joined the group.

There are about 270 detainees at the U.S. military base at Guantanamo, which was set up in January of 2002 to hold terrorism suspects captured after the September 11 attacks. Most of the prisoners have been held for years without being charged and many have complained of abuse.

More than 190 of the prisoners have filed challenges with the U.S. appeals court in Washington to the decisions by the military tribunals that they have been properly held as enemy combatants.

In April, Parhat's case was the first to be heard by a civilian appeals court.

In a one-paragraph notice summarizing its ruling, the three-judge appeals court panel said it issued its opinion on June 20 to both sides in the Parhat case.

Because the ruling contained classified information and information the government initially submitted in secret, a redacted public version will be made available later, it said.