Security forces have launched a two-month crackdown in the western Chinese region of Xinjiang in response to a string of deadly incidents.
Officials say they have established dozens of police checkpoints throughout Xinjiang, along with around-the-clock street patrols in city squares, bus and train stations and shopping centers.
The security crackdown coincides with the annual China-Eurasia Expo, which will be staged in the Xinjiang capital of Urumqi in September.
Xinjiang has been plagued by a wave of violence in recent weeks that has left more than 30 people dead. The Chinese government has blamed the unrest on Islamic religious extremists, but exile spokesmen for the region's native Uighur population say harsh Chinese repression is the real cause.
Tensions have been high in Xinjiang since 2009, when at least 197 people were killed during ethnic rioting between Uighurs and Han Chinese.
The Uighurs, a mainly Muslim, Turkic-speaking people, complain they are economically and culturally disadvantaged compared to the growing numbers of Han Chinese who are moving to Xinjiang.
Some information for this report was provided by AP.