Ethnic Uighurs from around the world have gathered in Japan for a meeting to press their case for independence from China.

Many Uighurs complain that they are the victims of state-sanctioned persecution and marginalisation in their homeland in northwest China, aided by the migration of millions of Han Chinese into the territory.

The resulting ethnic tensions have led to sporadic flashes of violence in the Xinjiang region, which is home to nine million Uighurs.

The exiled head of the World Uyghur Congress, Rebiya Kadeer, will on Monday open proceedings at the fourth meeting of the body in Tokyo.

Kadeer, who lives in the United States, is expected to say China's oppression of Uighurs is worsening and to ask the international community to monitor the situation in China.

China considers the WUC a "splittist" organisation and has condemned Japan's issuing of a visa for Kadeer, who last visited the country in 2009.

The World Uyghur Congress will see "hundreds of ethnic Uighurs from around 20 countries... gather in Tokyo to call for the right of self-determination," Ilham Mahmut, president of Japan Uyghur Association told AFP earlier.

The gathering comes after Japanese Prime Minister Yoshihiko Noda met his Chinese opposite number Wen Jiabao and South Korean President Lee Myung-Bak in a meeting that focused on economic ties and the response to North Korea.

This year's conference will be the fourth after previous editions were held in Munich, Germany and in Washington.