BEIJING (Reuters) - A senior Uighur official in China's restive western region of Xinjiang has admonished other Communist Party "cadres" from the mostly Muslim Uighur minority for failing to pull their weight in the fight against terrorism, state media said.

China has increased security in Xinjiang to fight what it sees as a grave threat from Islamist extremists stirring up ethnic tension.

Rights groups say that party restrictions on the religion and culture of the Uighurs create simmering resentment of the state and of policies that encourage the majority Han people to move to the region in vast numbers.

"I have become deeply aware, in these severely complicated circumstances, that we Uighur cadres have not taken on the bulk of the work (in fighting terrorism)," said Mehmet Emin Bekri, a top official in south Xinjiang's Kashgar city, according to a post on an official city account on WeChat, a popular social media app.

"(Our) work ethic is superficial, (our) stabilty measures half-hearted, and there is a clear gap between (our) security work and the demands of the central, regional and prefectural party committees," he said.

A former trading post, Kashgar is central to China's One Belt, One Road initiative, President Xi Jinping's signature foreign and economic policy that aims to create a new "Silk Road" of trade and infrastructure links between China and the developing nations of Euroasia.

But the city and nearby towns in southern Xinjiang are also among the most unstable in the region, creating a threat to plans that the party is combating with mass police rallies and a raft of new "anti-terror" measures.

"We must be soberly aware that... the infiltration of religious extremist thought is intense, the group influence is large, the scope wide, the level of poison deep, especially among people born in the 1980s and 1990s," Bekri said.

Bekri's remarks were published alongside photos of him meeting with white-bearded elderly Uighurs wearing traditional hats over meals of flat bread.

The party encourages ethnic minorities to become cadres, but Uighurs still number far fewer than Han officials in the region, and as all party employees are expected to be atheist, they are often seen by fellow Uighurs as having abandoned their culture.