Blood in the streets: Brutal rioting broke out this week in China's Xinjiang region between members of the Uighur ethnic group, Han Chinese, and government security forces. More than 156 people were killed in the riots in the capital of Urumqi, which began after police quashed a protest by students over ethnic discrimination. China has threatened to execute the leaders of the uprising -- while intervening to protect the Uighur community from ethnic reprisals. The violence has briefly focused global attention on one of the world's bitterest, but least-understood, ethnic conflicts. Above, an unconscious protester is pulled away from the fighting on July 7.

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