Chinese police have detained one of the country's most high-profile outspoken critics of state policies in the restive far-western region of Xinjiang, which is home to the Muslim ethnic Uighur minority group, the government said on Thursday.

Wednesday's detention, made on suspicion that Ilham Tohti "broke the law", is the latest indication of the government's increasing hardline stance on dissent surrounding Xinjiang, where a series of violent riots in the past year have killed at least 91 people, rights activists say.

Police in Beijing seized Tohti, a prominent Uighur economist who has championed the rights of the Uighur community in Xinjiang, at his home and his whereabouts were unknown, his wife and close friend told the Reuters news agency.

Guzaili Nu'er, Tohti's wife, said that about 30 police officers raided their home in Beijing on Wednesday afternoon, during a six-hour operation in which they seized his computer, mobile phone and some of his students' theses.

"Of course I wish he could come back home as soon as possible. What I also want to say is this time (the police raid) was different from previous times. This is the first time they have come with so many people," Nu'er said during an interview at their Beijing home on Thursday.

Many resent what they see as oppressive treatment by the government, though Beijing says they are granted wide religious, cultural and linguistic freedoms.

'Incitement for separatism'

Tohti, an economics professor at Beijing's Minzu University which specialises in ethnic minority studies, told Reuters in
November that state security agents had physically threatened him for speaking to foreign reporters.

Nicholas Bequelin, a senior researcher at Human Rights Watch, said that Tohti's detention reflected a harder stance that Chinese President Xi Jinping has taken on Xinjiang. State media called this a "strategy shift" from development to maintaining social stability.

Bequelin said Tohti could be charged with "incitement for separatism", which carries a maximum sentence of life imprisonment.

"The test of what constitutes incitement of separatism is anything that opposes ethnic harmony," he said.

Tohti, Bequelin said, was "an intellectual trying to get the state to see objectively what the situation is".

"He wants to tell truth to power," he said. "I cannot see anything that he has written or done that can be construed as
endangering state security. But the outcome is a foregone conclusion."

Source: Agencies