(Reuters) - Two "thugs" stabbed to death a policewoman in the Chinese region of Xinjiang where the government says Islamists are using violence to campaign for a separate state, media reported on Monday.

The motorcycle-mounted attackers used sharp weapons to "cruelly attack and kill" the policewoman, China Central Television (CCTV) said on its official microblog on Monday.

Media did not specify the ethnicity of the policewoman but judging by her name, she was Uighur, a Muslim minority that calls Xinjiang home. CCTV cited a colleague of the woman as saying she was two months pregnant.

The attack occurred on Friday near a market in Pishan county, in Hotan prefecture.

Heavy restrictions on journalists in Xinjiang, where China has attributed recent violence to Islamist separatists it says seek to establish an independent state called East Turkestan, make verifying details about incidents difficult.

Exiled Uighur groups and human rights activists say the government's own repressive policies in the region have provoked unrest, an accusation the government denies.