Officials from China's ruling Communist Party have supported violent attacks in restive Xinjiang, a top regional official said in remarks highlighting internal opposition to tough local policies.

The homeland of the mostly Muslim Uighur ethnic minority -- many of whom complain of discrimination and controls on their culture and religion -- is often hit by deadly unrest.

China blames the violence on Islamist separatists but rights groups point to Beijing's own actions as a driver.

Xu Hairong, the region's top anti-graft official, accused some local party members of participating in the unrest, pointing to a division in implementing Beijing's anti-separatist stance.

"Some communist cadres... even support or take part in violent terrorist attacks," Xu said in the state-run China Discipline Inspection News.

He did not give any details but added that some officials were "wavering on the big issues of opposing anti-separatism and maintaining ethnic unity".

The article Tuesday came days after authorities said Chinese police killed 28 members of a "terrorist group" in Xinjiang, in the bloodiest such operation in months.

It also came after the editor of the Xinjiang Daily, the Communist Party's mouthpiece in the region, was dismissed for what anti-graft officials said were offences, including publicly criticising party policies.

Authorities launched a "strike hard" campaign after a bomb rocked the main train station in the regional capital Urumqi last year as President Xi Jinping was wrapping up a visit to the city.

The crackdown, which has seen mass trials and multiple executions, has been condemned by human rights groups.

Xinjiang in China's far west is a resource-rich region abutting central Asia.

China's Communist Party is officially atheist and bans all of its officials -- including Uighurs -- from religious faith.

Schools and government offices annually attempt to stifle Ramadan fasting as part of the ban.

But officials persist in religious beliefs despite the policy, Xu said.

"Some waver in their ideals, are confused in their beliefs, not believing in Marxism-Leninism but believing in ghosts, and lack loyalty to the party," he said.