 Official sources state that the rioting began at around 2 a.m. , and there were reports that they lasted until at least 4 @.@ 30 a.m. , when police arrived . An initial disturbance was reported at around 11 p.m. when security guards responded to a call for help by a female worker who felt intimidated by several chanting male Uyghurs . Two dozen Han workers armed with batons and metal rods then responded ; they called for backup using their phones . 
 Official sources state that the rioting began at around 2 a.m. , and <a href='dey_it' title='1'><mark>there</mark></a> <a href='uninflect' title='2'><mark>were</mark></a> reports that they lasted until at least 4 @.@ 30 a.m. , when police arrived . An initial disturbance was reported at around 11 p.m. when security guards responded to a call for help by a female worker who felt intimidated by several chanting male Uyghurs . Two dozen Han workers armed with batons and metal rods then responded ; they called for backup using their phones . 
Official sources state that da rioting began at around 2 a.m. , and it was reports that they lasted until at least 4 @.@ 30 a.m. , when police arrived . An initial disturbance was reported at around 11 p.m. when security guards responded to a call for help by a female worker who felt intimidated by several chanting male Uyghurs . Two dozen Han workers armed with batons and metal rods then responded ; they called for backup using their phones .