From the BBC:
BBC News - Urumqi attack kills 31 in China's Xinjiang regionAttackers in China's restive Xinjiang region have crashed two cars into shoppers at a market, killing 31 people, Chinese media reports say.
They also threw explosives during the attack in the regional capital Urumqi. More than 90 people were injured, the state-run Xinhua news agency said.
IMO, China needs to act decisively before this terrorist threat gets out of hand. China can ill-afford to assume that economic development will bring an end to such a problem. Ethnic hatreds are fundamental and they generally are not impacted by economic conditions. Sufficient force, on the other hand, can lock them up so to speak so as to reduce the threat of violence.