Violence broke out in up to four neighbourhoods in the western Chinese city of Urumqi on Tuesday, according to witnesses. <br /><br />A group of armed Han Chinese people were seen marching towards an ethnic minority Uighur neighbourhood. Uighurs and security forces were also out on the streets.<br /><br />Al Jazeera's Melissa Chan reports on the third day of unrest in Xinjiang province, where authorities say 156 people have died so far.
