China has installed thousands of surveillance cameras in the restive capital of western Xinjiang province.
The move comes just days before the first anniversary of ethnic violence in Urumqi between the minority Uighur and the majority Han communities.
The cameras, which have a "riot-proof" protective shell, have been set up across the city, including at bus and railway stations, schools and shops.
Violence erupted last July, in which Chinese officials say 197 people died.
The government says about 1,700 people were also injured in the 5 July unrest, with Han Chinese making up most of the victims.
The violence, China's worst in decades, ended after troops were deployed, and security has remained tight ever since.
Xinjiang, a resource-rich region that borders Central Asia, has more than eight million Uighurs.
Many are unhappy about the large influx of Han Chinese settlers which they say has increasingly marginalised their interests and culture.
The cameras, which are being monitored around the clock, were installed to "ensure security in key public places, allow people of all ethnicities to enjoy quality public services, and create a peaceful capital," the Xinjiang Economic Daily reported.
It is part of a crackdown on violent crime in Urumqi.
Some 5,000 police officers have been recruited in the year since the clashes, and Urumqi's police chief Wang Mingshan said officers had been staging drills to deal with any similar emergencies.
Last week, police said they had broken up a gang behind a number of attacks in Xinjiang.
China's Public Security Ministry said that the 10 "hardcore terrorists" arrested had planned attacks in southern Xinjiang between July and October 2009.
He said they were also behind an attack in Kashgar in August 2008 in which 16 Chinese border police were killed.