Originally from the western Chinese Xinjiang Uighur Autonomous Region, the men were captured in 2002 by US forces in Afghanistan and sent to Guantanamo Bay for interrogation.

Although the exact number held is unknown - estimates vary from a dozen to 30 - they have been recently deemed of little intelligence value by the US military and it has been suggested that some of them might be released.

The problem now is what to do with them.

Risk of torture

Human-rights groups are saying that if they are returned to China, they run the risk of possible persecution, torture and execution.

James Ross, legal adviser to Human Rights Watch, a US-based rights-monitoring group, says: "America has a legal obligation to not send people back to countries where they might be tortured.

"China has a long
history of human rights abuse so we would be extremely concerned about seeing the government send
them back"

James Ross, legal adviser to Human Rights Watch

He added: "China has a long history of human-rights abuse so we would be extremely concerned about seeing the government send them back."

China, though, has said it wants them back. An ally of US President George Bush in the "war on terror", Beijing has said that there are strong links between its domestic "terrorist" problems and groups such as al-Qaida.

Western diplomats in Beijing have said in the past that the links are at best tentative, but China sees these prisoners as proof of that link and wants to question them further.

Beijing wants return

Suffering a series of bomb attacks and riots in the 1990s, Xinjiang is described as a sensitive topic when discussing relations between the indigenous ethnic groups, who are nominally Muslim, and the Han Chinese who make up 96% of China's population.

Uighurs form one of the largest ethnic minority groups in Xinjiang.

Exiled Uighurs have in the past publicly stated they want to see the re-establishment of East Turkistan, a historical state that once included Xinjiang and neighbouring parts of Central Asia.

China says the fact that the US military finds them of little intelligence is meaningless. In October, Abd Allah Mahsud, a former Guantanamo inmate, kidnapped two Chinese engineers in Pakistan. One later died during a rescue attempt.

Issuing strongly worded statements, China's foreign ministry has suggested that a failure to send them back could harm relations.

"The East Turkistan problem is part of the international war on terror. The US should respect the international cooperation against terrorism and respect US-Sino relations," said the ministry.

Complicated problem

In August though, US Secretary for State Colin Powell said the Uighur prisoners were a complicated problem but that they would not be sent back to China. It was also revealed that the Uighurs themselves had asked not to be sent back.

In Xinjiang, Muslim Uighurs form
a major ethnic minority group

However, a spokesman for the US State Department last week told Aljazeera.net that nothing had been finalised and that no one knew what was going to happen to the Uighur prisoners, suggesting that talks with China on the issue were ongoing.

"One possibility could be that they are sent back with diplomatic reassurances," says Nicholas Bequelin, an expert on Xinjiang and human-rights issues.

In such a case China would have to provide written assurances that the Uighurs would not be tortured or persecuted.

But Bequelin thinks that repatriating them with assurances would be unlikely because US public opinion would be against it.

"The Chinese prison system can be like a black hole. You send someone in and you never hear of them again, and America knows this," Bequellin said.

China's wrath

An alternative is to send them to a third country, but finding one willing to potentially incur the wrath of China may prove difficult.

"As China's weight has grown, so has its leverage," says Bequelin. "If someone took the prisoners, China could raise diplomatic concerns, take economic measures, or suspend academic relations."

In early November, Norway, which was approached by Washington as a possible candidate, rejected the idea, saying it was a problem the US should solve on its own.

One possibility has been for the European Union to split the burden of taking the prisoners, possibly linking it with the proposed lifting of the arms embargo placed on China after Tiananmen Square in 1989.

Failing that, the US could decide to take the prisoners themselves, or they could just stay in Guantanamo, permanent guests of the Pentagon.