A United States federal judge may have acted too quickly in ordering the immediate release of 17 Chinese Muslims from Guantanamo Bay, a three-judge panel said on Monday.

A three-judge panel for U.S. Court of Appeals for the D.C. Circuit is considering the fate of 17 Uighurs, who are being held in the military prison in Guantanamo Bay, and began hearing from the administration of President George W. Bush and lawyers for the detainees on Monday.

The detainees might need to formally apply to enter the United States via the Homeland Security Department, which administers immigration laws, the judges suggested during Monday's hearing.

"Before they can be admitted into this country, there are immigration statutes to be addressed, and petitioners haven't pursued that yet," said Judge Judith W. Rogers, who had previously expressed support for the Uighurs' immediate release.

The constitutional showdown comes in the wake of president-elect Barack Obama pledging to shut down the naval facility's prison.

Matter for president, not courts

Solicitor General Gregory Garre argued that releasing the detainees into the U.S. was a matter for the president to decide, not the courts.

"This appeal raises questions of diplomatic relations and national security that are for the political branches, not the judiciary, to resolve," Garre wrote in court filings this past week.

The Appeal Court is examining whether a federal judge has the authority to order the release of prisoners from Guantanamo who were unlawfully detained by the U.S. and who cannot be sent back to their homeland.

The 17 Chinese Muslims, who are no longer considered enemy combatants by the U.S. administration, have been held at the naval prison for almost seven years. They were taken into custody in Pakistan and Afghanistan in 2001.

They were cleared for release from Guantanamo in 2003 but feared they would be tortured if returned to China, where they are still considered terrorists.

China has argued that insurgent Uighurs, an ethnic minority group in Xinjiang, are leading an Islamist separatist movement.

Roughly 20 per cent of about 250 detainees who remain at Guantanamo fear torture or persecution if they return to their home countries, according to the New York-based Center for Constitutional Rights.

According to the centre, their concerns raise questions about where detainees should go if other countries refuse to house them.

Fears of diplomatic reprisals

Efforts to find an alternative home for the Uighur detainees outside the United States have been complicated by fears in many countries of diplomatic reprisals by the Chinese government, which has demanded the men be repatriated to China.

In October, U.S. District Judge Richard Urbina ordered the immediate release of the men into the United States, ruling that their detention had "crossed the constitutional threshold into infinitum."

But the Bush administration quickly blocked the order, citing security concerns over weapons training the Uighurs allegedly received at camps in Afghanistan.

The U.S. said it would continue efforts to find another country that would accept the 17 detainees.

"It's regrettable they are in this situation, but we are active in seeking another country to take them," Garre said.

The D.C. Circuit court previously agreed to temporarily halt the release to consider the government's appeal.

The three-judge panel includes two Republican appointees and one Democrat.

Two United Nations investigators recently told the D.C. court that based on their high-level meetings with foreign governments, "there is no third country of refuge for the Uighur prisoners now, or in the foreseeable future."

"It is our view that the United States is under international law obliged immediately to release the Uighur detainees of Guantanamo," Manfred Nowak, the UN torture investigator, and Martin Scheinin, the UN's independent investigator on human rights in the fight against terrorism, wrote in court filings.

More than 100 Guantanamo cases are under review by federal judges in the United States, following a Supreme Court ruling that detainees have a right to appeal to U.S. civilian courts to challenge their imprisonment.

Last week, a federal judge ordered the release of five Algerian men after rejecting government allegations that they were "enemy combatants."

U.S. District Judge Richard Leon urged the Justice Department not to appeal that decision, indicating the detainees had languished at Guantanamo long enough.

With files from the Associated Press