The rioting was sparked by allegations of sexual assault on Han women by Uyghurs , and rumours of an incident in which two female Han workers was sexually assaulted by six Uyghur coed @-@ workers at the factory , according to Voice of America . The authorities said that the rumours was false , and had been initiated by a disgruntled former co @-@ worker . Xinhua said that a man surnamed Zhu " faked the information to express his discontent " over failing to find new work after quitting his job at the factory .