Tension flared in China's western city of Urumqi on Friday, when hundreds of Han Chinese tried to push past security barriers into an ethnic Uighur neighborhood and shouted demands for better security, Reuters reported.
The confrontation came a day after many thousands of Han Chinese massed in the streets in Urumqi, regional capital of Xinjiang, protesting that they were the targets of mysterious attacks with syringes and that authorities had been too slow to punish Uighurs behind deadly riots on July 5.
China announced arrests and indictments over the July 5 violence between Han Chinese and Uighurs, a Turkic-speaking Muslim people native to the area, as officials sought to prevent fresh protests by Han Chinese.
But the flare-up showed the city remains volatile despite a security crackdown across the energy-rich region.
"They have no right to block off the road like this. These Uighurs have been stabbing us with needles," said one man trying to push through barriers sealing off a Uighur neighborhood.
"We need to take care of the problem."
Thousands of Han Chinese protested in Urumqi on Thursday. Some demanded the resignation of the region's veteran Communist Party Secretary after a wave of reports of attacks with syringes.
Later, troops carrying riot shields and rifles guarded city streets after authorities imposed a night-time curfew in response to the noisy 3,000-strong gathering in People's Square.
But the tight security failed to deter some protesters.
After the confrontation at the barrier, a group of about 50 young men who appeared to be Han Chinese, unfurled a Chinese flag and marched around shouting demands for "safety," followed by several hundred people. Police snatched away the flag, but the crowd continued shouting.
"The main thing is nobody here feels secure any more," said onlooker Zhen Guibin. Many people complained that those behind the killings on July 5 had not been tried.
A protest by Uighurs that day gave way to a spree of violence across the city in which 197 people were killed, most of them Han Chinese. Two days later, Uighur neighborhoods in the city were attacked by Han Chinese demanding revenge.