A Chinese man killed himself and injured two others when he blew himself up at an office building in Urumqi, capital of China's western region of Xinjiang, the Xinhua news agency said.

Han Wushun, an ethnic Chinese migrant worker from Sichuan province, demanded 4,500 yuan ($658.4) in wages from the Xinjiang Beixin Road and Bridge Construction Co. yesterday afternoon before detonating explosives he carried in a black satchel, Xinhua said.

Suicide bombs are rare in China, but disputes over wages could increase as an economic downturn leaves migrant workers more desperate.

A spate of incidents where unemployed workers blew themselves up took place in the late 1990s, when unemployment soared in many Chinese cities during the Asian financial crisis as state-owned firms went bankrupt.

Many Sichuanese have migrated to Xinjiang, an arid frontier region that is home to the Muslim Uighur people and other ethnic minorities.

Han had worked for the company for three months in 2007. He sued in a local court for the money early last year, but lost his case in July, Xinhua said.

The agency quoted an unnamed manager of the company as saying Han had been paid in full according to his contract.