By Michael Martina and Megha Rajagopalan
BEIJING, March 10 (Reuters) - China has arrested a Uighur AIDS activist for endangering national security, a health advocacy group said, in the latest sign of the government's crackdown in the troubled far western region of Xinjiang, home to the largely Muslim Uighur people.
Akbar Imin was detained in Xinjiang's capital, Urumqi, on January 15, the same day that prominent Uighur scholar Ilham Tohti was held by police in Beijing, the Aizhixing Institute said in a statement seen by Reuters on Monday.
Authorities later charged Tohti, who had championed Uighur rights, with separatism.
Imin, a former employee of the Aizhixing Institute in Beijing, was detained by police when he was in Urumqi for his father's funeral, the institute said on Friday, adding that police should "not politicise" the case.
"We call upon Urumqi public security and relevant departments to cautiously deal with cases that involve our Uighur compatriots who participate in social and public welfare activities," it said.
Well-known Chinese dissident Hu Jia, who also once worked for the institute, said the 32-year-old AIDS prevention activist knew Tohti but the extent of their relationship was unclear.
"I understand that the charges are endangering national security. This crime is broad, and includes the crime of separatism, the accusation made against Ilham," Hu told Reuters by phone.
Imin graduated in 2006 from Beijing's ethnic minorities studies university, Minzu University, where Tohti is an economics professor.
HIV is a persistent problem in China's urban Uighur communities, in part stemming from intravenous drug use, activists have said.
Li Fangping, Tohti's lawyer, said endangering national security refers to a broad category of criminal offences in Chinese law, including separatism and interfering with national sovereignty, among many others.
"Speaking broadly, crimes under the category of endangering national security carry a sentence of around 15 years," he said. "If this case is handled in secret, the specific charge against him may never be clear."
Unrest in Xinjiang has killed more than 100 people in the past year, prompting authorities to toughen their stance. Many Uighurs resent restrictions on their culture and religion.
China bristles at suggestions from exiles and rights groups that the unrest is driven more by unhappiness at government policies than by any serious threat from extremist groups who want to establish an independent state called East Turkestan.
Chinese officials have noted mounting anxiety and resentment between the country's majority Han Chinese and Uighurs since a knife attack in the southwestern city of Kunming on March 1 left 29 people dead and injured about 140 others.
Beijing has not explicitly accused Uighurs, but referred to the assailants as Xinjiang extremists.
Foreign diplomats in Beijing said last month that Chinese police have detained at least four of Tohti's Uighur students. Their whereabouts are not known.
Advocates of Tohti say he has challenged official versions of several incidents involving Uighurs, including one in Beijing's Tiananmen Square in October, that China says was its first major suicide attack.
His case is a sign of the government's hardening stance on dissent in Xinjiang, where Uighurs make up less than 50 percent of the population.
The United States, European Union and international rights groups have demanded Tohti's release.
He has said that he has never associated with a terrorist organisation or a foreign-based group and has "relied only on pen and paper to diplomatically request the human rights, legal rights, and autonomous regional rights for the Uighurs". (Editing by Nick Macfie)