BEIJING, CHINA - Police in China's Urumqi city have issued a list with photos of 15 suspects wanted in connection with ethnic unrest this month that the government says left 197 dead, state media said Thursday.

Police in the city, capital of the remote northwestern Xinjiang region, said those who turned themselves in would be treated leniently while those who did not would be 'punished severely", Xinhua news agency said.

Members of the Uighur ethnic group say the unrest was touched off when Urumqi police responded violently to peaceful protests over an earlier brawl at a factory in southern China that state media said left two Uighurs dead.

However, the government says Uighurs, most of whom are Muslim, went on a rampage in Urumqi against members of China's dominant Han ethnic group.

Xinhua reported on Wednesday that authorities had arrested a further 253 suspects in connection with the violence, in addition to more than 1,400 the government said were detained earlier.

Exiled Uighur activist Rebiya Kadeer however said in Tokyo on Wednesday that nearly 10,000 people had 'disappeared in one night' after the violent clashes.

Xinjiang government spokeswoman Hou Hanmin dismissed that claim, calling it 'not even worth a counterreaction", according to Thursday's English-language Global Times.

China poured thousands of troops into the city after the initial July 5 unrest and subsequent protest marches by thousands of angry Han armed with makeshift weapons.

The Chinese government accuses Kadeer of orchestrating the violence, but has offered no evidence. It has acknowledged police shot and killed 12 'mobsters' amid the riots.

Kadeer, head of the US-based World Uighur Congress, has denied any involvement in the unrest.