The regional government says initial investigations show the violence was masterminded by the separatist World Uyghur Congress led by Rebiya Kadeer.
It says the World Uyghur Congress has recently been instigating unrest via the Internet, calling on supporters "to be braver" and "to do something big."
The riot follows a violent incident between Xinjiang and local workers in a toy factory in Guangdong province on June 26.
Two Uygur workers were killed during the factory brawl and more than 120 people including 89 Uygurs were injured.
Nur Bekri said overseas groups exploited this fight, using it to undermine ethnic unity and social stability in the autonomous region, with an aim to split the country.
The government and Party Committee of the Xinjiang Uygur Autonomous Region paid great attention to the event and quickly called in the police. The situation is now under control.
After the July 5th incident, people in Urumqi have expressed strong anger and condemnation and have called for cherishing peaceful and stable social circumstances.
A Urumqi resident said, "I will hope from my heart that the society is stable, and every family is happy."
A Urumqi resident said, "Those who break the laws must be severely punished."
A Urumqi resident said, "They violated the normal social order, broke government order. They are smashing, hitting and looting."
A Urumqi resident said, "They smashed outside, everything. Half an hour later I came out and see this. We are terrified and don't dare go out. I think safety is the most important. A harmonious society is our most important goal."
The Urumqi city government has mobilized the proper departments to clear the roads and remove damaged cars to allow life to return to normal as soon as possible.
The Urumqi police have detained several hundred suspects, including a dozen leaders. They are tracking downing the riot leaders still at large.
(CCTV July 7, 2009)