Thirteen of the people killed were civilians while the other eight were alleged attackers. - AFP (File Photo)

KASHGAR, China: Tensions ran high in China's remote Kashgar city Tuesday after authorities shot dead two men suspected of fomenting deadly ethnic unrest and vowed a further crackdown on “religious extremists”.

Police killed the men, both from the mainly Muslim Uighur minority that makes up around half the population of China's northwestern Xinjiang region, late Monday as they were trying to capture the pair, Kashgar authorities said.

The deaths bring to 21 the number of people reported killed in Kashgar, a famed city on the ancient Silk Road in Xinjiang, since the weekend in the latest bout of unrest stemming from Uighur frustration at Chinese rule.

Thirteen of the people killed were civilians while the other eight were alleged attackers, some of whom were trained in “terrorist” camps in neighbouring Pakistan, according to Chinese authorities.

Xinjiang's government pledged to “firmly punish violent terrorists” and “crack down on religious extremists” in the wake of the attacks, which came just weeks after deadly clashes in Hotan, another city in the vast region.

On Tuesday, there was a heavy police presence on the streets of Kashgar, with some shops and businesses remaining closed, and few Han Chinese in evidence.

Many of Xinjiang's roughly nine million Turkic-speaking Uighurs are unhappy with what they say has been decades of political and religious repression, and the unwanted immigration of the Han, China's dominant ethnic group.

“Look at the Han and the Uighurs -- who is rich and who is poor?” said one Uighur man aged in his 20s, whose name AFP withheld due to the sensitivity of the issue.

“Some Uighurs go to university in Urumqi (Xinjiang's capital), they graduate, come back and can't find jobs. These all go to the Han. And even when they do find jobs, their salaries is low.”

The tension has triggered sporadic bouts of unrest in the resource-rich and strategically vital region that borders eight countries, including Afghanistan and Pakistan.

In July 2009, China was hit by its worst ethnic violence in decades when Uighurs savagely attacked Han Chinese in Urumqi -- an incident that led to deadly reprisals by Han on Uighurs several days later.

The official Xinhua news agency named the two men killed late Monday as 29-year-old Memtieli Tiliwaldi and Turson Hasan 34, and said they were shot dead in corn fields outside the city.

Police earlier issued warrants for the two and a reward of 100,000 yuan (about 15,000 dollars) for information leading to their arrests.

They were accused of involvement in an attack Sunday in which six civilians were killed when a restaurant was set ablaze, apparently after explosives were thrown towards it.

Kashgar authorities said Monday that the heads of the group behind the attack had learned explosive-and firearm-making skills in camps run by the East Turkestan Islamic Movement (ETIM) in Pakistan.

Chinese authorities have accused the ETIM, which wants an independent homeland for Xinjiang's Uighurs, of orchestrating attacks in the region on many occasions.

The United States and the United Nations have listed the group as a “terrorist” organisation, and China has previously said it has operations in Pakistan as well as Afghanistan.

Chinese state-run media has devoted little space to the attacks, and the words “Kashgar” and “terrorist attacks” appeared to be blocked on China's Twitter-like social networking sites.