Seoul  - South Korean immigration authorities stopped an exiled Uighur activist accused by China of terrorist activities from entering the country.

Dolkun Isa, 42, has remained since his arrival Tuesday at Incheon International Airport outside Seoul, officials said Thursday.

If and when Isa could leave South Korea was unclear.

Isa - the secretary general of the Munich-based World Uighur Congress, an exile group of the Chinese ethnic minority - has been on China's list of wanted terrorists since 2003. He has denied China's charges against him, saying the Chinese government considers all Uighur activities for self-determination, freedom and human rights as terrorist in nature.

Isa acquired German citizenship after fleeing China in 1997 and being given asylum in Germany. The German embassy in Seoul is looking into his case.

Isa's immediate release was demanded by The Hague-based international interest group, the Unrepresented Nations and Peoples Organization.

The group said he travelled Tuesday to Seoul to attend the World Forum for Democratization in Asia and claimed he was arrested at the airport on an Interpol arrest warrant.

"We believe that this arrest warrant was obtained by China to muzzle the most important Uighur human rights campaigners in exile," said Ulrich Delius, the Asia pointman for the organization.

Marino Busdachin, general secretary of the group, maintained that the charges against Isa were "fabricated" and his arrest "threatened the image of South Korea as a lodestar for democracy" in Asia. He urged Seoul to resist his extradition to China, where he faces the death penalty.

The Uighurs, who have long complained of discrimination at the hands of China's government, live in the north-western region of Xinjiang. Tensions between them and China's Han majority in the region erupted in July into violence, which continued this month with further clashes. They government said about 200 people were killed. (dpa)